I don't have any experience with that particular knife (NRA lockback), but the NRA stuff is made by Benchmade, so it should be a quality piece.

For slip joints I love Queen Cutlery, especially their Cocobolo line. Excellent D2 steel and very well made for not a lot of money. Canal Street Cutlery has some extremely nice stuff too (but expensive). Another excellent choice would be the Lone Wolf Loveless City Knife, though I think it's a bit above the price range you're looking in.