...come to think of it, the reason he gives for keeping the price at that of a basic potion like he was told he was worth is that it keeps it accessible for normal people and the people he heals are paying him out of gratitude...but when was the last time he healed a normal person? It's been nobles and elves for a bit and they didn't just pay him with money, they also tried to marry him as 'payment'. So, they're selling their body as part of the payment...
Normally, I'm for the argument of reducing or controlling prices for medical care, the need for which is often immediate and immutable, but I prefer actual arguments for that. In real life, there's plenty of issues that drive up prices without benefiting either the doctor or the patient. Insurance agencies, a banking service that frames itself as though they are providing treatment themselves, get their profit from taking payment from the patient but doing their best to deny payment to the doctor, tying up medical professionals time into arguing with them to, hopefully, get the pay their due. There's also the issue with pharmaceutical companies merely buying the rights to publically funded medical research and having produced little to no new medicine themselves.
In manga, an example that has a healer's guild that makes an argument would be The Great Cleric. It introduces the issue with the guilds out of control pricing with healers intentionally rasing their prices so that people have to sell themselves into slavery to afford treatment as part of a human trafficking scam. For others, the issue was that, with the regulatory body being crippled, they were collectively steadily raising their prices without any local competition by limiting how much they cross territory, the way ISPs work in the US.
However, the more I think about this, the more I'm reminded of the middle aged adventure with a 'game' skill manga/novel and it's 'humility/hiding his abilities' argument that it used as an excuse for the mc to be lazy, avoid responsibility, ignore the plight of is 3 loli elf wives while he cheats on them, impregnate 6 or more OTHER women, and abandon the kids all while this behavior kills as many innocent people as possible as he gives a speech praising his own humility literally in front of their corpses. That is, if this keeps up, it will feel like a half-assed argument the author insist on using to justify their plot points while serving as a cartoonishly bad example.