About a week ago I also was looking to buy a tire pressure gauge.
After a brief search I end up buying one from Radio Shack for $15:
http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=63-1114
The other model I considered was Accutire from Sears:
http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=TOOL&pid=02823001000
The primary reason I chose the one from Radio Shack is because it has backlit display,
though I believe that you can find other Accutire models that also have backlit display.
Note that this is the first tire pressure gauge I've used, so I cannot compare it against other
models, but so far I am happy with it. Note that the accuracy of those two models (and other
similar models in same price range) is approx. 0.5psi +- 1%, but this should be sufficient for
our purpose.
FYI, I am glad that I got the tire gauge, because I found that all my 4 tires on my 1 week
old Prius were under-inflated to 30psi. Fortunately, I have Coleman Powermate jumpstart
system with compressor (model PMJ 8161, approx. $60 on sale from PepBoys few months
ago), so this is another tool I'd recommend.
Hope that helps,
PR