Thermal printers are cheaper because you only have to buy paper, no ribbon or ink.
However, thermal receipt printers at restaurants seem to be among the cheapest ones around - you can get thermal printers that result in receipts that withstand decent temperatures (but, obviously, not all).
Many shipping labels are printed by direct thermal printers and those labels stand up quite well. Check Zebra for examples.
"Let's just tape this thermal receipt to your to-go container, and ... refund? What do you mean refund?"