When looking for used, Don't bypass the add that says 24 frame radial extractor.. I paid 100 dollars for my 24 frame extractor. It took some work and some camcoat to bring it up to working condition, but in all I have less than three hundred dollars invested in it.
I have found, honestly.. that older is better in most cases.. Like cars, extractor prices are going UP while the thickness of metal used in their construction is going down. My old AI Root extractor has cast iron base and top for the basket. The center rod is 1" in diameter.. I REALLY have to unblance it to make it start to dance.
With the smaller Maxant extractor I had, I found that it was not nearly as easy to use, and that I had more blowouts. My first ever use of the BIG extractor I had 0 blowouts. I think the sturdiness of the extractor contributes to this. With the maxant everything flexed, and i had to struggle with keeping the speed uniform.. it had a fiber washer type clutch you adjusted via a wingnut. It was quite unreliable and wasted a lot of power.. A single belt and a variable speed rheostat is a much better option and could easily be added at a later time.
If the price is cheap enough, a lot can be done to make a used extractor much more usable.