Do you know if your boys are interested in motorized Lego's? Our son tried them out at various times and was never interested in owning them. He used / uses the non-motorized Lego's. He just wanted more basic Lego's - at one point he wanted more of the rectangular & square bricks to make bigger and more complex creations. We ended up on eBay to buy the exact pieces he wanted. He will be 16 in June and used Lego's a lot up until age 15 and now it has tapered off a bit.
Lisa W.