Alternate suppliers - plenty of fly-by-nighters that won't be here 12 months from now (my experience from looking into this stuff 4 years ago). We have been looking at a product from Thales-Telematics for our industrial equipment. Communications to security station is via the mobile phone network, but the vehicles are actually tracked by satellite. They have their own back to base system similar to Quiktrak. I did come across other systems that were cheaper but alarmed back to your mobile if something was wrong with your equipment/car, then you would have to sort it out.
Trouble with Quiktrak is that they run their own towers, which is great for security, and they can have more control on tracking parameters, but they have more holes in the tracking network because of this, than do the other systems using mobile phone tower/satellite.
We looked into many systems about 4 years ago, and the satellite stuff was about $5000 then. Much cheaper now, and about the same price as a Quiktrak.