I have an airblaster (non-merino) and I absolutely love it. My wife has an airblaster in merino and she also loves it. When I compare the two, I wish I had gotten the merino version but by no means am I ever cold wearing my non-merino version.
If there was a merino airblaster for $89 I'd say scoop it up. But I suspect your $89.00 airblaster is the non-merino version. If that is correct, I'd definitely go with the Mons Royale merino for that price.