Like I said, being in the right place at the right time! That Up N Down was at a BIN for $35. I just happened to log onto to eBay at the right time and I snagged it. That Sector Alpha and Aquattack was from an estate auction website operated by Hines Auctions. It was linked in the ColecoVision Lunatics Facebook group. I thought for SURE someone else would have snagged them as I only put $100 each as my top bid. I ended up, totally to my surprise, winning one of them for $78 and the other for $99. I really didn't expect to win either of them.
I also ended up winning a lot of ten boxed Sega Master System games for $32 and a boxed Mr. Do!'s Castle for $40. Neither of those things that rare, but very reasonable prices. As I said, these were things I wasn't really looking for, but stumbled upon more accidentally.
Congrats on some great buys there. That Up n Down box is one I've coveted for a while. I've accepted I'll likely never get the box for Aquatack. Much too pricey. I grabbed a nice buy a while back on a nice CIB Sector Alpha which I was thinking was a great deal, but yours was even better than mine. All said you've had some great luck.