I agree with the fact that we just don't know what the real story on the situation is with the XB1 yet, could be anything, hopefully we have the whole story soon.
As to the bolded, you must be very young or not pay attention. There are a TON of extremely valuable used games out there. Pre-NES stuff is mostly worthless, but as of now there are quite a lot of NES through PS2-era games that are worth considerable money even CIB. New, as you say, can be crazy.
29 graded nintendo games : $5k+
http://www.ebay.com/itm/Nintendo-Lo...7807?pt=Video_Games_Games&hash=item2a2c26a9ef
Earthbound SNES : $3500
http://www.ebay.com/itm/Factory-Pla...4604?pt=Video_Games_Games&hash=item1c31e1eecc
Final Fantasy II Snes : $2225
http://www.ebay.com/itm/Final-Fanta...5469?pt=Video_Games_Games&hash=item2a2cb1a2bd
So you see, they can be pretty spectacular, but of course sealed stuff is silly in a lot of ways because most people don't collect sealed stuff while they're gaming.
But, if you take care of your stuff, a game collection can become retain some decent value over the years :
26 common open N64 games, $1000
http://www.ebay.com/itm/Huge-26-Nin...252?pt=LH_DefaultDomain_0&hash=item589be2e8c4
It's cool because if you hold onto your gaming stuff for 10+ years, you can eventually sell it for a decent chunk of change. My collection right now is worth in the range of $40k-$50k, and it's not even that huge (I kept a bunch of sealed stuff from the NWC era, as well as the grey). I have a 6 month old baby boy, and when he gets around 16, I'll sell half the stuff to buy him a safe car/truck, and save the rest to help with college.
So yeah, look into collecting. Even minty black-box PS2 stuff is on the way up. I have a good number of $100+ PS1 games that continue to increase in value. I'm not super sure if PS3/360 games will ever be valuable, but history tells me at least some of them will be.