We've all been there and done that, scouring eBay ha! I still search daily, but just in an attempt to find that elusive final box. You've done well so far, but your success rate will slow down and your price per figure will go up once you actually start searching for the uncommon neons.
I know, I figure that either my spending will go up or my collecting will drastically slow down as I look for those elusive colours in bundles.I suppose it all depends on how long I'm prepared to wait. Besides, I don't want to collect them too fast, there wouldn't be any fun in that.
I'm still counting on selling/trading my doubles, including premiums, at some point to make some money back so I'll see how that pans out.