Your right about postage, it's genuinely very high to post to America and i have had to pay high postage myself for items from America, it's worth it for the rarity what ever the postal cost, listing by auction is best 10 days and finishing on a Saturday or Sunday night that way you get max exposure and most people who don't work shifts like me are off work, when i buy from Ebay i'm 9 times out of 10 outbid on a weekend.
My theory is that due to high Internet auction exposure glass is as cheap as it ever has been as old items are surfacing all the time, (but then it's really cheap here even in antique shops), glass due to it's very nature gets damaged broken and chucked and i reckon there is only a limited supply of really good stuff which will dry up eventually as people like myself hoard it away.
The wire is not actual speaker wire it looks like it, not sure what it's official name is.