Teams that do shoulder joints or other large rotational joints will probably be interested in a large diameter 72-tooth #25 flat sprocket. I usually see 3-4 of these gigantic sprockets at any given regional, and usually there's some intricate pattern drilled into them to reduce weight. For simplicity's sake, I'd rather just drill the holes to mount the sprocket rather than worrying about part strength after machining, which no one on our team knows how to calculate or simulate.
Other than that I'm very interested in 22-32 tooth flat #25 sprockets with a bore large enough for a 3/8" ID bearing. Also, 14-28 tooth hubbed #25 sprockets with a 1/2" bore, keyed @ 1/8" or not keyed at all. That's the thing -- if we order online there should be a little "key this hubbed sprocket!" box for a couple of bucks more. Many teams have no way to precision cut a keyway (our Arbor press squeezed its way out of the tooling budget this year in favor of more needed accessories for the mill/lathe

).
Rather than directly compete with AM, perhaps it would be better simply to offer products that AM doesn't carry at the moment?