The verdict in three sentences
In 2026, a custom CRM-ERP connector costs between EUR 10,000 and EUR 40,000 depending on the number of flows and matching-rule complexity, with maintenance of EUR 150 to 600/month. It eliminates double entry between HubSpot or Salesforce and the ERP by syncing customers, orders and invoices. The choice between a standard iPaaS and custom comes down mostly to volume, conflict-handling rules and the need for real time.
Cost per synchronisation flow
Each flow (customer, order, invoice, stock) has its own cost, dominated by conflict handling and matching records across systems.
| Synced flow | Indicative cost | Direction |
|---|---|---|
| Customers/accounts | EUR 3,000-8,000 | Bidirectional |
| Orders/quotes | EUR 3,500-10,000 | CRM to ERP |
| Invoices/payments | EUR 3,000-9,000 | ERP to CRM |
| Products/prices | EUR 2,500-7,000 | ERP to CRM |
| Stock/availability | EUR 3,000-8,000 | ERP to CRM |
| Conflict handling | EUR 2,000-6,000 | Cross-cutting |
The most underestimated item is conflict handling: what happens when a customer exists on both sides with different data? Without a clear rule, sync creates more mess than it fixes.
iPaaS or custom: real time, latency and maintenance
An iPaaS (Make, Workato, Zapier) starts fast but bills per operation; custom costs more to build but becomes economical at high volume.
| Criterion | iPaaS | Custom |
|---|---|---|
| Setup | EUR 4,000-12,000 | EUR 10,000-40,000 |
| Cost by volume | Rising | Fixed |
| Latency | Batch to hourly | Real time possible |
| Complex rules | Limited | Unlimited |
| Monthly maintenance | EUR 100-400 | EUR 150-600 |
| Profitable at high volume | No | Yes |
Simple rule: below a few thousand syncs per month, iPaaS wins. Beyond that, or if you need real time and fine business rules, custom pays off in 12-18 months.
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Mini case study
Thomas, sales director at a 50-person B2B services SME in Lille, suffers double entry between HubSpot and his ERP: every order is re-keyed manually, i.e. 8 hours per week for the admin team at EUR 32/hour, or EUR 256/week and ~EUR 13,300/year, with 3 to 5 % billing errors. He invests EUR 24,000 in a bidirectional customers/orders/invoices connector, maintenance EUR 350/month (EUR 4,200/year). Double entry disappears (-8 h/week), errors drop below 1 %, net annual savings reach ~EUR 9,100 excluding error gains, for a payback under 24 months and reliable billing.
FAQ
How many flows should I sync at the start? Begin with 2 high-impact flows: customers and orders. You cover most of the double entry before adding invoices, stock and prices in stages.
iPaaS or custom to start? An iPaaS validates the need cheaply if volume is low. Once you exceed a few thousand monthly operations or conflict rules get fine, custom becomes more profitable.
Do I need real time? Rarely for the whole sync. Real time is justified for stock or availability; for customers and invoices, hourly sync is enough and costs less.
How do I handle data conflicts? By defining a master system per field (ERP is authoritative on invoices, CRM on pipeline) and deduplication rules. This is the priority point to frame in the quote.
What is the maintenance cost? Budget EUR 150 to 600/month depending on the number of flows and how often CRM/ERP APIs change. Plan an annual review to absorb tool evolutions.
Let's scope your project. Tell us your tools (CRM, ERP), priority flows and monthly volume: we will scope the connector, indicative budget (EUR 10,000-40,000) and maintenance. 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.
