Your question would need a bit of clarification.
Unbounce is a platform that allows you to quickly build, A/B test and launch landing pages.
PayPal is a payment processor.
Unbounce doesn’t process payments and it’s up to you to integrate and use your payment processor of choice.
Having said that, you can set up 3 different variants for your landing page that each would have a different price ($650, $600, $550). That is, if you want to see which price point converts better.
If you are looking to have all 3 on the same page and allow the visitor to pick one of the 3 based on some other condition, you can do that as well.
If you provide a bit more clarification on what you are trying to achieve and the flow you need, I’m sure the community here can point you in the right direction.