I've sponsored the development of a PayPal Buttons Module to add the ability to pay for single-item purchases using PayPal Buy Now and recurring purchases using PayPal Subscriptions. Both types of purchases will go through PayPal Website Payments Standard, not Express Payments or Website Payments Pro, which allows easier setup and administration.
The module will also optionally integrate with uc_subscribe, allowing greater flexibility in subscription management.
The initial quote for the module was $850, but it may come in less than that. We're currently testing the module, which is compatible with UC RC2.
[Feel free to move this topic to another board as appropriate.]