This is a real problem with rye. I still kick myself for not buying a case of Rittenhouse Bonded (the 100-proof black label) when it was under $15/bottle. Now it’s about $26 or so. The comeback of rye has also resulted in a hell of a lot of “me too” ryes that are sourced from MGP. While MGP’s rye is indeed good, there’s a lot of BS flying around (*cough* Templeton *cough*), and you should look before you leap. The thing is, such BS is unnecessary - in the Scotch world, independent bottlers and blending houses have a long tradition.
A good clue that a rye was distilled by MGP is if it touts a mash bill of 95% rye. That’s a hallmark of MGP’s product.
One newcomer that I found to be a very pleasant surprise is Jack Daniel’s Rye. While I consider Old No. 7 overrated, JD Rye is reasonable, well-made, 90 proof, and their own product.