A buddy of mine worked in a tire shop for an uber-anal boss, back in the 70s. The boss-man demonstrated why my $0.99 K-Mart special was worse than having nothing at all - its inaccurate readings were causing me to constantly over-inflate my tires (bad news). The boss' shop used to sell these $25 Austrian things (and back then $25 was a LOT of dough). He had a box of various shapes/sizes/brands of tire pressure gauges - and would happily demonstrate how many garden-variety gauges were giving readings +/- 10% of an accurate, high quality gauge. On a bike, that can be very important.

Interestingly, a couple of highly rated gauges are made in China. Check out these reviews:

Review # 1

Review # 2

Here's a mini article about tire gauges, albeit for RVs, but raises some good points:

Article

Accutire gauges are available on taobao. Less expensive than in the USA via some online shops.