I've never heard of the non professionally applied expoxy holding up, and the guy I had quote told me he cuts old garages gaurantess in half versus new.
And he wanted just over 2k to do my new, 16 x 25 floor.
Now keep in mind this isn't a daily use garage, and only my SL goes in there now.
http://www.knudsons.com/images/Garage009.JPG
go to
http://www.knudsons.com/kevins_garage.htm
I think the total bill was about $230, that includes a bunch of extra tiles, and exterior mastic. I do have to be careful, jack stands directly are a no-no, I put them on a piece of ply wood.
But after 8 years, I'm pleased, it cleans up and looks sharp.
The only problem I've had is the hot exhaust / tires shifts the tiles. I resolved this by putting the rear tires an a couple of rubber backed entry type mats.