Genesis once bubbled...
I have a major drysuit manufacturer's dealer price list here. Its essentially 50% of "list" price. That's a 100% mark-up, and DUI's products are price-controlled with that nice little "maximum discount" clause.
Assuming you offer a the maximum 20% discount off the "MSRP", on a $1000 suit you would sell it for $800 but pay $500 for it. That's a $300 profit on a $500 item, or a 60% profit margin.
20% over cost eh?
Nobody would sell an air card if all selling one meant is that you lose MORE on each fill (since there is typically a volume discount)
Yet they all do around here. And what is clear to me, when the Nitrox card is $9/fill (Q10) and the air card is $4/fill (same Q10), yet the O2 in the tank costs $0.80, and that's assuming I have to send back each "T" with 40 cubes or so in it due to lack of a booster (they have one), its pretty clear that they're not losing their shirts on those Nitrox cards.
I have, several times, explained possible ways out of this box for you. You have dismissed all of them out of hand, but I bet you haven't spent $10 in your corporate counsel's office finding out if what I've been talking about would actually work.