"The reserve at twice the opening bid?  Not a 
custom I've heard of."

my mom is an antique dealer and she sells and buys
stuff at live auctions all the time, so yes, the
reserve is normally twice from the opening bid
(give or take of course).


"And on online auctions, 
not if you're trying to minimize listing fees."

i think they base the fee on the reserve price,
not the opening bid and if the reserve is not
made, then the seller doesn't get charged a final
value fee.  so it doesn't matter what the opening
bid is, though, as a courtesy to the buyers,
people really should base their opening bid as
half of the reserve.


"(In which case, also, check the listing text, as 
many sellers put in what the reserve is.)"

i have never seen anyone devulge their reserve
before.  i mean what's the point of the reserve if
you tell people it in advance!?