As an added plus - since everyone and their brother is bailing out of the 27" tires in favor of upgrading to 700c, bike swaps are a goldmine for cheap 27" tires. The last one I went to I scored 27" folding tires for $2.00 each.
Nashbar has a housebrand 27" tire for less that $10.00. They just had a sale last month for something like $5.00 ea, and currently have some for $2.95.
Check this out:
Nashbar Tires
John D.