I have a call out to trade augers in the swap and sell but then I thought what about just trading "bits"? I guess you'd have to have an 8" power head beefy enough to spin a 10" bit but if anyone is interested PM me.
FWIW most power heads will run a 10" bit fine.
I have a 3hp Strikemaster with 10" ripper blade and I run it on my Tanaka TIA-305 power head that is under 2HP with no issues.
What auger bit are you wanting to trade?