Shipping from the UK is not bad, I buy from the auction site there often, and Royal Mail Small Packet is usually 2-3 pound, so less then $5.00 US . Might be worth it if it is hard to find.
fwiw I was selling my own 1/21 Honeywell Pentax Spotmeter and realized the battery issue after the auction ended. I communicated with the buyer and told him it was no good without the adapter, and we electronically shook hands and walked away. My cost was about $10 for the auction seller fees, but its worth it to keep a good auction rep. I'm mostly a buyer there and a sometime seller.