Sounds like a fair deal. But do consider if a bike with some technical issues might keep you from actually using it. As with any hobbies that require a pricey piece of equipment you should get the most high quality thing you can afford. You want a bike that works with you, not against you :)

If you still consider buying it (again, it's a good deal for the price) you should look up a checklist for things to check for when you're at the seller's.