Rare / low production guitars are holding firm, but not sure they are going up much anymore. I just sold an James Olson 12 String I bought 4 years ago, and made $750 on the sale. Broker I bought it from was selling it to another client. There were only 11 of them built, and it brought $16k. New in 2005 it was probably $8-10k. The above $5k range takes longer to sell.