The verdict in three sentences
In 2026, a custom B2B scheduling and booking web app in Dublin costs between 25,000 and 65,000 EUR, over a 3 to 6 month timeline. A monthly SaaS (10 to 40 EUR/user/month) looks cheaper upfront, but becomes more expensive over 3 years beyond around 40 active users. The real custom advantage: automated notifications, calendar integration and business rules impossible to model in a generic tool.
Cost per functional block in 2026
A booking app is built in layers. Here is a 2026 order of magnitude for a project delivered by an experienced team.
| Feature | Indicative price (EUR) | Timeline |
|---|---|---|
| Slot engine + calendar | 7,000 - 14,000 | 3-4 wks |
| Resource/team management | 5,000 - 10,000 | 2-3 wks |
| Email + SMS notifications | 3,000 - 6,000 | 1-2 wks |
| Google/Outlook sync | 4,000 - 8,000 | 2 wks |
| Online payment / deposit | 4,000 - 9,000 | 2-3 wks |
| Business rules (lead times, quotas) | 4,000 - 10,000 | 2-3 wks |
| Analytics dashboard + exports | 3,500 - 7,000 | 2 wks |
Break-even point against SaaS
Let's compare a custom build at 45,000 EUR with a scheduling SaaS at 25 EUR/user/month, over 3 years.
| Nb users | SaaS 3-year cost | Custom 3-year cost* | Winner |
|---|---|---|---|
| 10 | 9,000 EUR | 55,800 EUR | SaaS |
| 25 | 22,500 EUR | 55,800 EUR | SaaS |
| 40 | 36,000 EUR | 55,800 EUR | SaaS |
| 60 | 54,000 EUR | 55,800 EUR | Tie |
| 100 | 90,000 EUR | 55,800 EUR | Custom |
| 150 | 135,000 EUR | 55,800 EUR | Custom |
*Custom = 45,000 EUR + hosting/maintenance 300 EUR/month over 36 months (10,800 EUR).
Beyond 60 users, custom becomes cheaper, not counting specific features and freedom from vendor lock-in.
Mini case study
Marc, operations director of a maintenance SME in Dublin, manages 80 technicians and 500 client appointments per week. His current SaaS at 28 EUR/user/month costs 26,880 EUR/year, i.e. 80,640 EUR over 3 years, with no fine-grained route management.
A custom app at 48,000 EUR with route optimisation and Outlook sync saves 6% of unnecessary travel. On a fleet running 220,000 EUR/year of fuel and associated labour, that's 13,200 EUR/year saved. Added to the 26,880 EUR of removed SaaS, the return on investment lands in around 15 months.
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FAQ
How long to build the app?
Budget 3 to 4 months for a booking engine with notifications and calendar sync, 5 to 6 months with payment, advanced business rules and route optimisation.
Can it sync with Google Calendar and Outlook?
Yes, via the Google Calendar and Microsoft Graph APIs. Two-way sync avoids double bookings and reflects busy slots in real time.
Isn't SaaS safer to start?
Below 40 users, yes, a SaaS is often the best choice. Beyond that, or if your business rules are specific, custom becomes profitable and frees you from vendor price hikes.
Can we add online deposit payment?
Yes, with Stripe or a local gateway. A deposit cuts no-shows by 20 to 35% depending on the sector, quickly paying for the module.
What maintenance cost should I expect?
Budget 200 to 400 EUR/month for hosting, monitoring and fixes, plus an annual evolution budget of 10 to 15% of the initial cost.
Let's scope your project. Tell us your user count, your booking rules and the integrations you want (calendar, payment, SMS) with an indicative budget. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
