lxgreen, the basic fee for an ad is $4.00 for 30 days on Audiogon. Maybe you clicked on the green box that says "create a listing" which costs $10.00 per ad.
@phd , that $10 fee is only for items <$1,000.
In this case, the items value is between $3,500 - $9,999, the listing fee is $100, which @lxgreen has said that he's already paid for previous listings.
Big difference between $4 and $100.