PAIGETRAIN:
Since you're open minded regarding scale, my suggestion would be Bachmann's HO "Rail Chief". The set contains a nicely detailed and decorated BNSF GP40 and several pieces of decent quality rolling stock. Unlike many of Bachmann's boxed sets of years past, the components in this set are of high quality and the locomotive is a smooth runner. The package also includes trackside accessories. There's a lot of play value here. As far as price is concerned, the set can be found at the upper end of your range such as right here:
http://www.modeltrainstuff.com...rack-p/bac-00706.htm
Whenever I give a set as a present, it's the Bachmann "Rail Chief". It has not disappointed me or a lucky recipient yet.
Good luck.
Bob