It always amazes me that many of our members throw out these numbers for "truing" an action without being a little more specific regarding the details. You can get an action trued for as little as $100. Now, before someone tries to pile on and says " oh yeah, well what give of a job can you get for that?", I suggest you call GA Precision and ask them. Most anyone on this forum that has any tenure knows of their work, it's top tier. This said, prices can be upward from there depending on the services performed on the action. When y'all start talking numbers in the $500 range, do us a favor and break down what you're getting for that kind of money. Usually you're talking about taking a Remington action and customizing it with a new bolt, side bolt release, bolt knob and truing services. While these are nice features, they're overkill if you're looking for a basic, trued action that will get the job done at an affordable price.
I do agree that if you are going to buy a factory action and have it customized with all the "bells and whistles", you're better off buying a Stiller or one of the other actions up the price chain, but you can still have a good factory action trued without breaking the bank.