If what you're talking about is what I think you're talking about... There's no such thing as an inexpensive bore scope. Hawkeye is about the least expensive and those are up over $700 these days.
Saying that, if you go through a lot of expensive barrels they are a fantastic tool to own. I went in halves on one about 10 years ago. When I got out of Benchrest, I sold my interest to my co-owner. Not a big deal when we lived 5 miles apart... more of a deal now that we live 1200 miles apart.
Get together with 3-4 (or how ever many people you are willing to share with) friends and buy one... you won't regret it.