In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
if using outdoor reset.
the modulating unit will run longer at a lower rate. This will give it a better seasonal (I'm not 100% positive this is the right term) efficiency.
The fixed firing rate will equal modulating at design conditions only (with no zones) but will shorten run time with lower heating load. (decreasing seasonal efficiency).
my .02 worth.