The more elaborate $100-400 rails are cool and all if you have a use for them. Lots of people put them to work. But if you don't (I don't, as I prefer simple and light), it's really tough to beat the $25-40 MOE options.
I have a $300 Daniel Defense Omega X on a gun (the gun is a DD, so it came with it). It's a fine rail and plenty comfortable and light. But for now I have to confess its utility is being wasted. I just don't make use of it. Looks good though.
I like my MOE lined rifles just fine. I'd advise buying one, it's a low-risk investment.
"The Future is Unwritten"