Do you Known Editing and Amending Wordpress Plugin?

Plugin (User Profile Made Easy) looks wonderful to me. I need to customize plugin and need to know what would be the charges.

Customization:

1) Recommend Button in the user profile, for e.g. my profile http://profileplugin.com/profile/muhammedshoeb%20mirza/
- If clicked, few fields will come such as your name, date, textarea where the guest person will write comment to the profile person.

2) My profile will have prebuilt tip amount like the following way
Tip Amount : 2.50$ (), now either the guest person will increase or decrease it.

3) Gift Options : There should be dropdown in the following way,
Pencils - 5.50$
Pen - 10$
Inkpot - 10$

Guest person chose any gift if he/she wants to give to ME

All these options are just a not-required. They can recommend it without paying tip or gift or simply recommend it without gift or tip, BUT recommend is important.

Once these all done, they must be ask if they'd like to signup.

IF NO

then they must be taken the payment gateway (paypal) to pay for all these to ADMIN (woocommerce better)
- After payment is done, the User profile (frontend) will be updated with
Recommendations (1), once click it will show the
At the backend of the User profile, they must able to see,
Who Recommended them
What tip amount they paid?
What gift amount they paid?

IF YES
Register them in the website....and in their backend they must see, to whom they have recommended and what amount they paid and what gift they gave..