Harbor Freight has low priced toque wrenches that oftern can be had for $10-$11 each (on sale or with coupon). They offer 1/4", 3/8, and 1/2" models all at about the same price, and they come with a Lifetime Warranty. Magazine Reviews are pretty good too.
If you want higher quality, you can get click type or beam type torque wrenches from Sears, but the warranty is only about 90 days. Seems ridiculous to pay 8-10 times as much and get virtually no warranty.