I hope this doesn't seem too much like "Let Me Google That For You", but they're not too difficult to order from Japan. Can you boot the cut tire to ride while waiting for overseas shipping? It's been a while since I bought anything from them but I seem to remember shipping didn't take too terribly long.
Notice how Grand Bois becomes "Grand Bore", I think because the Japanese characters are transliterated phonetically. It's a good enough translation to get the job done though.
The non-EL standard casing is just ¥4000, under $40. Shipping will be a bit high, but the tires will still be cheaper than getting them retail in America, if you can even find them.
If I recall, the way shipping works is you put the quantity you want in your shopping cart, then wait for them to get back to you with the shipping cost. Might wait a day due to the time zone. Then you can cancel if it's too high, or pay and complete the deal.
I paid with PayPal, which handles the currency conversion for you, easy.