When people compare peptide prices, they often compare two things that are not the same product. A 503A compounding pharmacy is a state-licensed US pharmacy that prepares a medication for an individual patient after a provider writes a prescription. A website selling the same-named compound as "research use only" is not a pharmacy, involves no clinician, and is not regulated for identity, purity, or sterility.
The price difference between those two channels is real, but it is not a discount on the same thing. It is the difference between a dispensed prescription and an unverified chemical. This directory only lists the former.
That is why every price here carries a verification date and a source link, and why the sourcing model (503A, 503B, or FDA-approved) sits next to each provider. The point of the tool is to compare like with like.