Custom optin form creation and integration with Hatchbuck CRM

I'm trying to gather data in an optin form (basic info: name/email), plus the info from an online survey (6 or so "custom fields" with answers from the survey tool) and was told by the CRM provider that could do this with an http post. The recommended steps are: 1) Build your form in the CRM form builder and ignore the design, only capture the fields. 2) On your own website, write all of your own HTML/CSS/whatever to submit the form back to my web site, (according to them there is 0 dependence on Hatchbuck for this piece). 3) Then, after capturing the data on your own site you need to write a program (PHP/Node/.NET/Java/Python/Ruby/etc...) that collects the data from the WordPress website form submission and sends it to Hatchbuck as a POST with the fields/formid/etc. I'm looking to understand what my budget needs to be to make this happen.