In reply to:

Now if Axiom was willing to replace the m80s with m60s free of charge (ie pay for my return shipping on the m80s), I would do it.

To the best of my knowledge, Axiom does this. When I opted to upgrade my M22 to M60s, during the 30 day grace period, Axiom paid for the return of the 22s. That was my experience. Policy may have changed since then, but if not, they might pay for the return of the M80s, AND return you the difference in cost. You should give them a quick phone call, and ask.

Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton