i picked up a sled this year, after doing some research i found that if you want to double up slopes and do laps off the sled you need a 800 with around a 150 track. $3000 will get you something that will work.
i just use my sled to get me and a buddy up long access roads and then split into steeper terrain. I picked up a 99 summit 500, for $350. with similar miles. had to throw a hundred at it, and clean the carbs to get it running nice.
most companies got ride of the swing arm suspension in the early 2000's, i think it was 04 on the summits. makes the sled ride much better in deep snow.
tgr has a 50 page post about sled skiing
brandywine is a classic snowboard zone, its been in movies for years, going back to the forum 8/wildcat days, and still today in the yes movies. deep snow so you need a big sled. with all that traffic there should always be a road punched in.