Paypal Payment Wordpress Form

We are looking at integrating a membership signup form on a website. ie: we wish to automate the process as much as possible

I'm after a form that works like this:
http://www.parentinguk.org/our-work/membership/register/

The fields needed are attached in the documents.

the form would need to send the captured data to an email address as well as save it as a Wordpress post draft.

On submission it would also need to redirect and action a Paypal subscribe payment button. similar to what is at the bottom on this page
http://isanuk.org/join

Please could you let me know what the cost would be for integrating an online form like this onto this website, in place of the current ‘contact us’ form: http://isanuk.org/contact\

Thanks