My local shop carries the DML Abrams kits (they produce four different ones). They are marked at about $18 and are some of the better M1A1/A2 kits out there.
Trumpeter also makes 3 or 4 M1A1/A2 kits and they are very nice kits themselves. They run under $20 and have various options like mine plow or mine roller.
Tamiya makes the M1A1 with and without plow. It is the easiest to build but are not very accurate, especially if you want to do an Gulf War 2 tank. These are quite expensive, over $30.
Academy's is a cheap knock off of the Tamiya kit, they added a few detail items. Mine cost less than $20.
Italeri has just released a new M1A2 kit. Brand new tool and it looks pretty good. Mine cost me $20 + $5 shipping from someone online. Looks to be the best of the lot, but don't discount the DML kits. They still hold up nicely.
Trumpeter's are the best overall value, 2 sets of track per kit, mine roller or mine plow (depending on boxing).
Avoid the Esci M1 or M1A1. They were also boxed by AMT/Ertl. Not worth the plastic.