A horse at full board costs €375 per month at my barn (the Netherlands) with walker/paddock service 5 days a week. The barn has a small indoor of 17x50 (3 indoor lunge rings) and a 106x23m large indoor and an all weather outdoor of 75x80m with a jumping course in half of it. Training is not included but most trainers here ask between € 300-500 a month for full time training. So then it will come to €675-875 per month.
9-something-hundred €/month for board at a full care stable with great facilities and 400€/month for a training package which includes the staff putting the horse in the walker up to 7x a week and 5x lessons/trainer riding my horse