What would you do?

I recently bought a preamp at E bay to assemble a second system at home. In the AD , there was no mention on the method of payment, so when i offer to do paypal, the seller decline and insist on money order or cashier's check mail to him first before he mail the preamp.I feel uneasy about it and request the transactin done via cod. the seller wouldn't do it initially states someting about he has to paid 4 to 9 dollars more for cod ground ? ONe day later , he agree and wants me to pay 9 dollars more. NOw I am having second thought on the whole deal. Not so much on the extra 9 dollars but maybe it's lemon?