I worked with GPS modules a couple of years ago. They are getting very small and very low power. The cost seems to be about constant at about $100 in qty 1 (depending on source) and below $25 in qty >
10,000, perhaps as low as $15 in very high quantities.
They mostly use similar interfaces. The on-module CPU talks to the outside world via either a serial port (typically TTL levels) or some use USB. You need to provide an antenna. Typical units are either a "patch" about 2" square or a helical coil. A helical coil can be made yourself by winding small gauge wire on a core. It might be easier though to build your own patch which is just two layers of copper on a PC board. If you search a bit on the web, you will find significant info on building your own GPS antenna.
I have been thinking for awhile about building my own handheld GPS receiver and I am leaning toward using a commercial Bluetooth GPS receiver rather than an integrated module. I like the decoupling of the two units although it is a bit more awkward having two batteries to keep charged. The technology improves and will be taking a big step in the next couple of years as the European sats become part of the overall network. Also there are new frequencies and capabilities being added which will give better accuracy. Using an integrated module will make it much harder to upgrade to keep your GPS receiver up to date.
Check with a rep to make sure you can get the parts at the price advertised. We designed in Tyco and we were just told that the line was sold to a different manufacturer and device we specified is no longer available and/or has about doubled in price.
Take a look at the Delorme GPS2058. I've used it's predecessor, the GPS2056 in a few projects. The GPS2058 is smaller, but uses about the same power (50-75mA at 3.3V). It requires only a few external resistors and capacitors. The toughest part on many of these modules is getting a good 50-ohm microstrip on your PC board between the module and the antenna connector.
The modules are in stock at DigiKey for $41.65, qty 1.
If you want a module with an integrated antenna and only need a few, look at the offerings at
That is a pretty good price from what I have seen. But the power consumption is a bit high. IIRC, state of the art units as of two years ago were using on the order of 30 to 40 mA (average) at around 3 volts. When I did the survey the two leading lines were FastTrax and U-Blox. But I don't know how available they are to small volume users.