Making a custom form and get payments

Hi , i want to make a form where i can accept payments.
I need to ask many questions in my form, and then according to that answers , price should be calculated.
here is a video explanation of what i want

Disregard first 5 seconds

https://www.loom.com/share/b0a69c64ec4c4ba6a2e0177c9130ab54?sharedAppSource=personal_library

is it totally possible with your forms with free plan ?
Do i need to purchase anything else to get payments?

Looking forward to your response.