Hi Troy,
There could be some security issues involved with allowing users to register using someone else's PayPal account (sponsors). However, you may be on to something here.
You can use an instance of Dyn forms for your sponsors to be charged a flat fee upfront via PayPal. You can then keep something like a 'balance remaining' table that maintains how much money they have remaining to sponsor. Then you can use another instance of Dyn Forms for the users to register. This form will reference the table and deduct the registration cost from the sponsor's balance. So basically, the registrants will draw from the 'sponsor bank' and not from the PayPal account. Not sure if this is actually "easier" but it might be an option for you. What do you think?
Candace