The puzzle with pricing transfers for me is the fact that we have come to expect a discount on quantity, but with heat seal, one quickly reaches a point of diminishing returns in that, unlike screen printing, it takes 100 times as much time to press 100 pieces as it does one.
Not so in screen printing as. especially with an auto, most of the time is in pre-press, and clean-up.
Bottom line, you really have to time the process, and then price it accordingly.
You may even find that ordering the transfers will make sense on some jobs.