Need advice on 2010/2011 328i CPO purchases

I'm looking to buy my first BMW, either a 2010 or 2011 328i, CPO. I've narrowed it down to these 2 choices (Los Angeles area), and would love to get your opinion on them:

Option 1:
Price: $26k
Year: 2010
Mileage: 20k
Warranty: 4 yr/50k warranty ends early 2014, 2 yr/50k CPO ends early 2016
Color: Monaco Blue
Options in addition to value package: leather seats, moon roof, Assist
Time on lot: a couple months

Option 2:
Price: $27k
Year: 2011
Mileage: 28k
Warranty: 4 yr/50k warranty ends mid 2015, 2 yr/50k CPO ends mid 2017; extended maintenance plan to mid 2017
Color: Grey
Options in addition to value package: leather seats, moon roof
Time on lot: just added

My main concern is to minimize cost of ownership for the next 3-4 years I'm gonna drive it, and be able to sell it at the best price. I drove both and they were pretty much identical. How much wiggle room is there in the price, and how useful is that extended maintenance plan on option 2? I've heard some say it's basically just breaks, oil/filter, which might be less than the supposed $2k price of the extended maintenance plan. If useful, what would be a fair price to negotiate for as an addition on option 1 car?

As well, I have read elsewhere CPO can be a rip off? Is it a better idea to buy used then add on an extended warranty (heard it's ~$2k, would love some pointers on this as well)? As well, is it a good idea to get a PPI? Some argue it can uncover issues even on these relatively new vehicles, others say most things are covered under the warranty.

Any help is greatly appreciated!