Here is what I would say: instead of "By this description...has ended", change to: I have done my best to accurately describe and photograph my item. Please study pictures carefully, and ask any questions you might have before you bid-I will answer best of my ability, and as quickly as possible.
Then, "AUCTION PARTICULARS: This item can only be paid for by wire transfer or cashiers check. NO PAYPAL CAN BE ACCEPTED AT THIS TIME. If you cannot pay by the only ways I can receive, PLEASE DON'T BID! I will send winning bidder an email right after auctions end, and we will formalize how payment is to be made."
Just my suggestions, because I don't know where you are or if the rules are different-what about shipping-what did you say about that? What about insurance? Are there countries you won't ship to? I know this is a pain, but it is better to spend 20 minutes beforehand than endless hours afterwards trying to sort out what is a pretty simple transaction.
The main things you want to do are: describe and photograph well; remind to ask quesions before they bid, because a bid placed is a person saying "I want what you have photographed and described"; tell them to wait for you to contact re: how are you going to pay, and do this as soon as you can, and
don't send the bag until the payment has cleared! I hope this helps, I have learned so much from tPF!