Variable product price - Options problem

My magazine client needs to sell one, two and three year subscriptions as well as fixed price products like books and t-shirts.

The question is do I use eCart4 Rules or PS Options to create a subscription setup? I think it is Rules because it appears that PowerStore will only allow an Integer on the Price line on the Insert and Update pages in the Admin and I need three prices.

Soooo, I think that means I have to have a price as a base and then create Rules that will change the total based on a dropdown selector of subscription length coupled with a Session variable? Or, can it be done with the PS Options?

Also, when I do create an option, like Gift?, with a No default, a Yes value and unlimited product, and make sure it is all Online, the Details page price box displays "checking availability" and a little rotating progress indicator and then freezes on the live site and does not check at all on the testing server. Sometimes it shows in the Cart, sometimes not! What to do?

Thanks,
Jay