I paid $150 a month for my guy while I was redoing my barn. It was not a retirement farm, but it was not a show barn. He lives out 24/7 with two large shelters. He was fed 2x a day with food I provided and I had him trimmed by my farrier but there were other quality farriers who came to the farm. The grass was good and in the winter hay rolls were provided. The owner lived on property and she had four of her own horses. She would check him over every morning/night and she contacted me with any major issues.
So I paid around $200 a month with feed/shoes factored in. I trusted my horse there and I knew he was cared for like he was one of the owners own horses. I bring him over when I go out of state with the other horses for the summer and fall season for a month or two.
You can find places, just need to scout a bit. I recived advice from others on retirement facilities and I just was not a fan of leaving my horse at a facility where they stated that I would not be welcome to come see him or make decisions on his well being. Yeah, not working for me.
Different strokes for different folks I guess. If you need some suggestions for FL I know of a few that arent “retirement facilities” but boarding barns that are less expensive and meet the requirements, feel free to PM.