When I discovered the wide world of MesoRx and Tracy way back when, he was pretty much the only one posting any kind of meaningful price list. In my early experience trying out countless Chinese suppliers it became clear that such a price list was the exception and that the rest seemed to prefer pricing on-demand and many expected some degree of haggling/negotiation as well.
This is actually quite common with a lot of Chinese sales reps across countless industries, and I suspect it's based on the same approach as a car salesperson feeling you out to see how much they can charge you.
Many more peptide suppliers are providing prices publicly now, but I've elected not to make it a requirement quite yet. I've been considering making it a requirement (at least for GLP-1's) starting the first of the year, but I'm also weary of scaring off what could turn out to be really good suppliers solely because they lack a price list. Like everything else here, it's a delicate balance.