I have a very little used GPINT for sale, it is no longer required as I now use a QHY5 camera which has a built in ST4 port. The GPINT unit compatible with a very wide range of guiding packages and mounts, full details can be found here:
http://www.store.shoestringastronomy...roducts_gp.htm
The new cost is USD 35 and you on top you would pay another 10 or so for shipping, I am asking AU$ 15 inc postage to anywhere in Australia.