HubSpot Developer fees

I was asked by the COO of a fairly large local nonprofit if they should use HubSpot for their CRM. I haven’t ever used it (I worked for a Salesforce shop before I built my organization’s custom CRM).

The use case is fairly straightforward (logging interactions with client’s family members, guardians, etc.

They were leaning toward using HubSpot, because it was a “free” tool for nonprofits. I think many organizations jump into tools like this because they don’t understand the development costs associated with them. However, I have no idea what a typical HubSpot integration costs.

I know this is most likely a vague question given the limited information, but I’m curious to know what most people pay (roughly) for a custom integration and ongoing development fees.