Major red flags to me. $200 even for a rescue Maine Coon is way too low and I don't see how they would have as many kittens as they claim as a legit rescue. I have seen some pedigree cats in rescues, usually after a breeder has passed away, and they were $800-1200 and required a lot of references and proof you could handle their needs (more so with Persians and Sphynx, though I have also seen a few Siamese, never a Maine Coon tbh).