Web integration with donations

I’m wondering if there’s any free or not overly expensive web integration scripts or similar which enable me to have a website with lots of buttons, that do 2 things, let you donate a fixed amount, and in return, runs a rcon command on my gmod server.
I would want things like…

Button that says Low Gravity [$5]
$10 to set the server to low gravity for 5 minutes

A rank
$10, you get given a rank etc

and a few more things that are similar. Is it overly complicated to integrate it like this? or should I just hire someone to do it?

(I have searched and viewed many tutorials)

If you wan’t free ones, then you need to search the internetz yourself and try to fixx them up.