Tydes has a good reputation as a single vial seller. So do other companies like Skye. Eros is another with somewhat less info on them but better prices. There's about 5 single vial sellers that I hear consistently good things about quality. However, with ALL of these: You are comparing your pricing to compounded, so the pricing won't seem that bad to you. But realize that if you are willing to start buying the powdered peptide that you have to reconstitute yourself, you might as well go a bit further and look at how you can order an entire "kit" which is 10 vials. Because these entire kits often cost the same as what 1-2 vials costs on Skye or Tydes, or others.
That said, nothing really wrong with a single vial order from a trustworthy place. Ultimately, buying kits can be safer because you can get together with people to do your own testing, so you don't trust the word of the vendor. (Did they really send the vial from that batch in to get that Jano COA?)
You'll be ok with your Tydes purchase, but keep looking into this.
P.S. every time you check out with one of these single vial vendors, request a complimentary bottle of "bac water" and many times you will get it! Especially with Skye.