I am lucky to be able to keep mine at home now. But I have boarded at a few nice places in the area. This is "North Central Pennsylvania"
By far my favorite place to board costs $250 per month (current price). Each horse has their own run-in shed with tack room, heated auto-waterer, 1/3 acre sacrifice and 1 acre grass when it is green and growing; horses are separated by hot-high tensile. Includes hay, grain (Triple Crown), blanketing, holding for vet/farrier, bedding, shed clean-out once per week, any medicating if they need it. Outdoor arena, round pens, and a few hundred acres of farm to ride on.
Another one is also $250- field board. Horse lives out with a few others and share a run-in. Hay is provided; you provide grain. Blanketing is included. You hold for vet/farrier. Nice indoor arena, rough-footed outdoor, some on-farm trails.