Not entirely true about contacting before payment is made.
Basic Listing:
http://support.audiogon.com/customer/en/portal/articles/1035913-listing-guidelines
Basic Listing:
- All communication regarding the negotiation and sale transaction must take place onsite. You may not provide any type of contact information until after an offer has been accepted.
- Include your contact information
http://support.audiogon.com/customer/en/portal/articles/1035913-listing-guidelines