I usually do 2 prereleases and get a ETB for every set. Then I buy singles and full arts for cards that I think my be useful in the future. I've also been slowly chipping away at collecting older sets. Buying $20-$30 worth of commons, uncommons and rares once a month or so. Then if I see a cool set of sleeves I tend to pick those up too. All in all I probably spend $1000-$1500 or so a year.