hi dave,

its a difficult question. in theory both boats are old and from experience I would rate and expect the quality of the boyer higher than that of the bim. if there is a 2nd hand market for carbon masts and sails, upgrading the boyer later might be a good idea. alu masts are out of use for a long time already, so nearly impossible to find a newer sailcut on the 2nd hand market for these.

the bim comes with a carbon mast which I treat as a plus. depending on the brand it might not be the most reliable one so. bimare/bandini have quite some history for mast breaking easy, but than again if this mast lasted already 11 years it might be a solid one. basically it comes down to boatshandling. most mast break in capsizes or pitchpoles... and you can be lucky your mast can deal with that abuse or not... but it needs the sailor and conditions to create that situation first :-)

really no clue if the alu spar is more durable than the bim carbon spar? maybe someone has knowledge about it?

what I like onb carbon, even a broken mast can be fixed again. that is actually also a good source for looking for a 2nd hand package. I once bought a repaired broken marstroem spar (so also a marstroem can break ;-) ) with a landenberger sail (both 1 season old) for around 2.000 US$ and while having an undamaged identical mast as well, I mostly raced the repaired one. It was slightly stiffer which was favourable.

If you are not in a hurry, maybe Tom's advice to wait and see is not such a bad choice... while on the other hand both offers do not sound too bad too ;-)