It definitely looks like it's been "rode hard." When you look at the beam shining on the wall, does it look "clean"? Does it have concentric circles in the spot? Do you know what the mW output is? Do you know what the Amps in is? Does it start quickly? Does it drop out or flicker?
I have never paid that much for one, but that is mostly because I'm a very patient eBayer. If the spot looks "clean" and it is putting out its rated mW at no more than 8A, then it is probably good. If those things are true then the only question left is, "Is a 488nm room heater worth $250 to you?"
If it works, then I'd say yes!! You can always clean it up. Or if you want something a bit cleaner, like dave said you can surf ebay and be very patient. Do your research to find out what model is best for you. When it comes to these 'smaller' argons, some do 40mW balls out at 10A, others will do 40mW just barely above an idle. I'd suggest reading through sam's FAQ and find out which is best for you. I kinda 'shot first and asked questions later' when it came to mine, but I got lucky and it turns out the unit I got would be the model I would have been looking for, had I not had the urge to impulse buy ;D
Appreciate all the info guys. I personally have not seen it. I'm going to go have a look at it today. Anyone else interested if I decide not to cough up the cash?