The price sounds good for a 4wd if it is in good shape. You can get parts for them but be prepared to wait a little. It usually takes anywhere from 3 to 4 weeks to get parts from Japan. I am not trying to discourage you from buying one however. The Iseki tractors are one of our best sellers and are a really solid, durable tractor but I just wanted to let you know in advance.
If you have a local AGCO dealer, you might try ordering an Iseki parts manual for your tractor, getting the part number for the part you need, and taking it to the AGCO dealer. Iseki & AGCO are partners. The new AGCO Challenger is basically an orange Iseki. We have had some luck with at least a few of the Iseki part numbers working with AGCO. You will need a really cooperative dealer!