As has already been mentioned, you really shouldn't have a need to replace all the chainrings at once. It's probably just the ring you spend the majority of your time in that'll be worn, usually the middle chainring on a triple.
Lots of options for replacement chainrings out there in just about any tooth count you can think of. Google or ebay the tooth count you want and make sure you're getting the correct BCD (bolt circle diameter) and that it's the correct number of arms/bolt holes (4 or 5 arm) and get whichever one suits your fancy. Low mileage used ones can be found pretty cheap on ebay. Depending on the area you live in and the kind of bicycles are prevalent, your local bike co-op (if you have one) might have what you need for dirt cheap.
If you're replacing the middle or large chainring, you can usually even remove those without removing the entire crank though pulling the crank typically isn't all that hard.