I am just getting into bikes and I found a nice GT Outpost at a fair. It is fairly beat up with a bit of rust, but I took it for a spin and rides okay, brakes work. It looks like something from the late 80s, early 90s. I'm not too familiar with bike parts, but the frame says Ishiwata Chrome, many of the parts say Exage system and the chain system says Shimano. It is 18 speed. I think that's all that I jotted down, let me know if you need additional information. It's going for around $100. Just wondering if it's a fair price for this worn out, but still fully functional bike. Thanks!