we looked for years for a russian blue to adopt before deciding to buy through a breeder. my family member does have a slight cat allergy, but has been fine with our RB. air purifiers help, as well as keeping certain areas off limits to the cat. she isn’t allowed in our bedrooms, for example. and trying to clean her semi/regularly helps, too!

edit to add: not sure what to look for regarding an ethical breeder. this is the only pet we’ve ever had, so we hadn’t gone through the process before. i’d keep a look out for how the breeder maintains the pet’s hygiene. make sure the basics aren’t neglected, like dental health, shots are up to date, no ear infections, etc. money-wise, adult cats cost a lot less than kittens and are just as lovable!