"Chris Friesen" wrote:

However, I think that wiring all the 240V circuits with #10 is overkill
given that it costs significantly more than #12.

Not really, think full boxes of wire, not cut lengths.

Standardize on one wire size, buy full boxes(spools) of wire and get a
better price.

Even if it cost 15-20% more up front, there will come a day
when.....................

Lew