Tesamorelin quotes span a rent payment and I’m confused

I’ve been trying to compare tesamorelin without turning it into a hobby. My little notes file has six quotes for a 30-day supply ranging from $310 to $980, which is too wide for me to read as just shipping or vial size. In the trials it was studied for visceral fat in a specific population, so I get that my curiosity is not the same as evidence. I’m not asking anyone to name a source or tell me what to use. I just want to know what makes the low end plausible: batch size, cold-chain, testing, clinic markup, or something else? For those who’ve compared prices, did you settle on a per-mg or per-month number you could actually defend? I’m mechanism-minded enough to want a rationale, not a bargain.