Hello, right now I do similar thing for mdb database but using own php form where new client fill himself.
Ok, as for your project - how many fields need to send into your PipeDrive database.
Better if you will provide exact appointment form that going from Acuity Scheduling.
And how they are going to PipeDrive -as you've said "I have almost gotten it to work myself" - I think you have working example or video as you do it by hands.
As for my bid - I just set it to 90 usa dollars, if this work much easy -- I will decrease that price. Just I'm not sure about it easy or not. Sometimes small important details can bring a lot of headache and seriously increase the time of completion.
Thanks, have a nice day