OK, my bad, I checked, Thelyron actually DO sell Healing stuff (a regeneration scroll, and a resurrect scroll or spell...) However, he sells no healing potions, while the market magic vendor do sells some. So I am not entirely wrong here, some coherence opportunities are missed here.
All hope is not lost, although it is tenuous.
There's still plenty of reason that he and other NPCs should offer single character or party wide healing services. Maybe if you do him a favor or a quest he will offer them for free or give a discount.
From a gameplay perspective, this is a mechanic that needs to be in game in some form or another. Things like resting at a campfire or getting a room at an Inn can still be added for roleplaying purposes or for healing as well. The more options the better.
