My Plan for Game Buying Next Generation

I have been looking over some numbers and things like that.  My attach rate on the Xbox 360 was around 70 retail titles (many on sale later in the generation) and probably about 100 XBLA games.  I've decided that I probably can't afford that many games this generation.  So what did I decide?

Amount: I've decided that I can buy up to 4 retail games per year or up to 13 downloadable games.  That is unless I win a lottery jackpot netting $37 million (a guy can dream can't he) whereby I would purchase all readily available retail game released for the Xbox One in the US.  That would likely be a lot of USB 3.0 external hard drives.

Format: I've decided to get games on disc based (retail copies) after I looked at some of the size estimates for Xbox One games (though I can't really see games getting much larger than 49 GB).

The games (for the most part) are too large to download even if you have a decent internet connection (anything over 20GB takes way too long to download).  My stance may change a little bit based off of digital prices and sales (and whether or not I have to pay sales tax, if I don't digital copies become more interesting).

Miscellaneous Stuff:
* External hard drive: i'm kind of curious about what size external hard drive I would need for my Xbox One.  Something between 2-4 GBs might be enough for a couple of years.  Come on MSFT add the option a little earlier. 
* Achievements: I would really like to get my Gamerscore up to 100,000 by the end of this next generation - my last, this time I really think I mean it.
* Windows 8 Apps on Xbox One: this has been sort of rumored, there are definitely some Windows 8 apps I would like to play on my Xbox One (or at least offload storage to the Xbox One, since I barely have any space on my Surface).  Maybe this could be used as a backdoor kind of way for backwards compatibility for  XBLA games.  I would be interested in playing some controller enabled "apps" like Ty the Tasmanian Tiger on my Xbox One. 

Sequels:
i don't see much of a reason to get sequels within a generation this time.  In other words, i'm interested in Forza 5, but i probably wouldn't get a Forza 6 or 7.  Though a Forza Horizon 2 could be interesting.   i'm not sure how interested i am in a new Halo (maybe one, but not two).  Some games, maybe the sequel will be different or a continuation.  However, that is the burden of proof these in generation sequels need to prove to me - is it more of the same (a Forza 5 to 6 or another Madden game) or is it something a little different?  i'm ok with multiple game story arcs (trilogies, etc).