Several comments have already been made but I'll throw in my $0.02.

I have bought several "cheap" scopes in the past and have kicked myself for doing so. Got dinged a few times either from the scope bezel itself or the scope jamming my glasses into my nose. OUCH! I use the word "cheap" to define quality, not price.

I have three Bushnell scopes that I feel are well built and quite adequate for the guns/barrels they are mounted on. They are not very expensive, $90-200. One is on an Encore 12 guage slug barrel and it is the new model with 6" eye relief. This scope is great for this purpose. T/C has a crazy scope base that only fits this barrel and puts the scope further forward. The long eye relief really helps. I also have a 6" eye relief scope on my 209x50 barrel. The one thing I don't like about the Encore is the stock design. The recoil tends to kick the gun up into your face instead of straight back so these LER scopes really help on heavy recoil barrels.

I have a couple of Leupolds on dedicated rifles and they have about 3.5" of eye relief. I think that is fine with a high quality scope like this. The eye relief stays constant through-out the magnification range so I don't have to creep up on it at higher levels.

One thing I did not see mentioned here is how to properly mount a scope in regards to eye relief. Make sure that the scope is set to it's highest magnification level and position the scope for the proper eye relief. Everybody reading this probably already knows this but just wanted to make sure. I like to do this from the offhand position. You never know when you may get a shot and I just want the gun to naturally go into position without having to adjust my head to see through the scope. This may put the scope closer to your face while at the bench or in the prone position but you should have more time to adjust your head before taking the shot.

Last but not least is my advice to buy a "quality" scope. I don't think you need to drop $1200 on a Swarovski but don't buy a $40 cheapy either. Like BigCountry said, I have swapped scopes onto different rifles because I always seem to be buying and selling guns but I keep my scopes.