Conditional Redirect For PayPal Transactions

It would be really great if we could implement a conditional redirect for those checking out with PayPal vs. a Credit Card.

The main use case for this would be on a single sales page that includes an upsell (via the Thank You page redirect) and two methods to pay: PayPal or Credit Card. I know PayPal cannot process Upsells, but it would be cool if we could redirect them to an entirely separate TY page, so ONLY those with credit cards will be taken to the Upsell. This would save from having to create a separate page for PayPal transactions in the case where upsells are offered for the same product, but different gateway.