10x would be ridiculous, but so far LEGO's limited run models means that if you buy a popular model at the end of its run for its normal store price, you can effectively double that money by just having it in a closet for 1~2 years. Are you going to get rich off of a LEGO buy-now-sell-later scheme? Heck no. But is it a perfectly sensible way to double a small amount of money over a 1~2 year period? Absolutely.