I dont think its very low Billy, I think in a plain jacket with a standaed nib then that's about right, put a special jacket o it with a higher quality nib then you will be able to push that price boundary further.
Its only my opinion and as always is subjective, it's based on what I have sold in the past to what I believe you can get in the market for a half decent fountain pen.
But don't let it put you off, when you sell one for a few hundred then pm me so I can jump on the bandwagon and become millionaire along with you.:wink: