Custom Software vs Off-the-Shelf SaaS: 3–5 Year TCO Compared

The right way to compare custom software and SaaS is total cost of ownership (TCO) over 3–5 years, not the first month's price. SaaS costs grow with user count; custom software costs $10,000 once for an MVP or $30,000–100,000 for a mid-size build, plus 15–20% annual maintenance, with no per-seat multiplier.

What is TCO and why does it matter more than upfront price?

TCO is the sum of every cost a system incurs from purchase or build through years 3–5: subscription fees or build cost, implementation, integration, maintenance, and the labor cost of workarounds when a tool lacks features.

The upfront price is only the starting point. A SaaS tool that looks cheap at signup can become more expensive than custom software once you count per-seat fees at scale, paid add-on modules, and the staff hours spent manually bridging workflow gaps. The two cost structures run in opposite directions: SaaS scales with headcount, while custom software stays largely flat after launch. That is why comparing costs at a single point in time tells you almost nothing.

What goes into a 3–5 year TCO model for SaaS?

The short formula: (per-seat fee × users × 12 months × years) plus implementation and data migration, paid add-ons, integration middleware, and workaround labor. Most businesses underestimate the last two.

Line items to model:

• Subscription cost at your projected headcount in years 3 and 5, not today's. This is the largest hidden driver of TCO growth.
• Tier upgrade cliffs: many SaaS products push the entire account to a higher plan once a user threshold is crossed.
• Paid add-ons: advanced reporting, API access, SSO, and multi-entity support are often gated behind pricier tiers.
• Integration cost with accounting, inventory, or in-house tools, which the SaaS vendor rarely covers.
• Workaround labor: spreadsheets and double entry when the tool doesn't match your process.
• Data exit cost when switching platforms, since some vendors intentionally make export expensive.

What goes into a 3–5 year TCO model for custom software?

Custom software TCO = build cost (once) + maintenance at 15–20% of the contract value per year + any planned feature phases. There is no per-seat multiplier and no forced tier upgrade as headcount grows.

For build cost, FutureTech's published pricing gives the reference points: MVP from $10,000 (6–10 weeks), mid-size builds $30,000–100,000 (3–6 months), large systems $100,000–350,000+ (6–12+ months). Annual maintenance of 15–20% covers bug fixes, security patches, and operational support. It is the main recurring item, and it does not scale with user count. Cloud infrastructure is billed separately but is usually small compared with the SaaS subscription it replaces. Whether you have 10 or 200 users, the software cost stays the same.

How do you calculate the breakeven point between SaaS and custom?

The simplified formula: breakeven years = custom build cost ÷ (annual SaaS cost − annual custom maintenance). Since SaaS cost scales with users while custom maintenance is flat, breakeven arrives sooner as your team grows.

A worked example with a mid-size build:

• Custom build cost: $60,000 (within the $30,000–100,000 range)
• Maintenance at 18% per year: $10,800/year
• Equivalent SaaS at 40 users: assume $25,000/year (illustrative, since real SaaS pricing varies by vendor)

Breakeven = 60,000 ÷ (25,000 − 10,800) ≈ 4.2 years. Now change only the headcount to 100 users, pushing the SaaS bill to $60,000/year after a tier upgrade: 60,000 ÷ (60,000 − 10,800) ≈ 1.2 years. That is the key insight. A custom build looks expensive for a small team but pulls clearly ahead as headcount grows. Run the formula with your own quotes and your 3–5 year headcount projection.

When does SaaS make more sense, and when does custom win?

SaaS wins when the team is small and stable (roughly 15–20 users), the workflow is genuinely standard (accounting, generic CRM), and you need to be live in weeks. Custom software wins when headcount is growing, your process is distinctive enough that SaaS needs constant workarounds, or data ownership and freedom from per-seat lock-in matter to how you plan to scale.

If you are not ready to commit, FutureTech offers a middle path: a free custom-configured ERP (inventory, sales, basic cash flow) set up for your business. It is free to run, with fees only for additional modules you commission, so you gather real usage data before making the TCO call. For Singapore businesses, the EDG grant can cover up to 50% of qualifying custom software project costs, tilting the balance further toward custom. Note that PSG applies only to pre-scoped packaged solutions. As a Vietnam-based partner working specifically with Singapore clients, FutureTech builds to an ISO 27001-certified security standard and coordinates in English on Singapore business hours, so choosing custom does not mean giving up local-grade security or day-to-day contact.

FAQ

Is custom software always cheaper than SaaS over 5 years?

No. The outcome depends on headcount, how standard your workflow is, and your SaaS vendor's tier structure. Small, stable teams on standard processes usually do better with SaaS; growing teams with distinctive workflows usually do better with custom. Run the breakeven formula with your own numbers.

What is the biggest hidden cost in SaaS TCO?

Workaround labor, the manual work staff does when the tool doesn't match a business process, combined with per-seat tier upgrade cliffs as headcount grows. Both are almost never shown on vendor pricing pages.

Does custom software have ongoing costs too?

Yes: 15–20% of the contract value per year in maintenance. The structural difference is that this cost does not scale with user count the way SaaS subscriptions do, which is exactly why the two TCO curves diverge over time.

At how many users is the typical breakeven point?

There is no universal number; it depends on your build cost and your SaaS vendor's per-seat pricing. In this article's example, breakeven moved from 4.2 years to 1.2 years just by growing from 40 to 100 users.

Can I switch from SaaS to custom software later?

Yes, and many businesses do once SaaS costs cross the breakeven point. When timing the switch, budget for data migration and the SaaS platform's exit costs, since some vendors make data export considerably more expensive than others.

Reference pricing — an exact quote follows a free scoping session.

Want to compare TCO with your own data? Book a free scoping session with FutureTech at ftech.ltd, and we will model both scenarios before you decide.