I just look at it like a savings account. If i used to tuck away 500-1000 a month in savings where it sits and has no gain. Instead I can see true growth over 6 months to a year by investing this money into legos. Buy smart and stay on budget. Then after a year or two of doing this you should have a nice little nest of which to pull from so you never have to leave those sales on the shelf! Good luck