After searching some online dealer sites, it looks like you're getting a deal. A NIB 1100 is going for around $900+. I'd buy a couple extra O-rings in case they deteriorate (which is pretty common among Remington auto-loaders IME). Also, I believe this model is 2 3/4 only, and may limit its effective range should you decide to take up upland game or waterfowl hunting. Here's a couple links for price comparison purposes:
Bud's
Gun Broker