[schlagwerk]

The Jet Man mecha aren't the worst*, but before that... whoo boy. $300 would be cheap. I dream of getting Bio Robo (thankfully it got a Godaikin release that goes for a few hundred cheaper), Change Robo, and Flash King. But I've seen the latter 2 go for $500+ on Yahoo Auctions Japan. These days I casually look for options, and then just watch how much they go for.
You know you're in deep crap when you want a truly collectible item. On that isn't just unreasonably marked up on eBay, but that actually sells for several hundred on even the Japanese market. Transformers G1 Overlord & Star Saber are like that, too.

*I still feel lucky with what I paid for my Jet Icarus & Jet Garuda. I paid out the butt for middle-man fees, but still got both for under $200 each because I was willing to buy ones with a couple of curling decals and no instructions. I even got the boxes for them!