I agree with the post above. Go ahead and buy what you will need later. I feel like if I bought the 500r or other products that look like that, I would be endangering my animals because of many things I would have running off of it. If I only had one to three animals and did not want any more, then I might pick one of those. I'm not downing those thermostats but I will say that I do not think they are professional grade. To each his own.