In a past post Questions about the Lyman bore cam where discussed.  A friend just recv'd one and I got a chance to try it out today.
I purchased one of the $14.00 Ebay scopes and found it a great toy for the price. But I can tell you that the Lyman unit is so much better that there is no way to compare the two. 
The $14.00 unit is well worth the money but if you want to see in your bore and be able to tell the condition the Lyman is the way to go.
The Lyman views at a 90 deg. angle to the bore and shows every machine mark or pit or what ever.
I am not sure that what you see will really help in our shooting but if you want to make your self wonder how your rifle shoots as good as it does take a look with one of these.

Dale