2016 or CPO 2013-15? Crew Cab 4x4 Long Bed

I have a 2002 Extended Cab Manual 4x4. Recently the 3rd cylinder has been causing me trouble (troubleshot everything for the p303), so I'm looking to buy my second Tacoma.

In shopping, I'm comparing Certified Pre Owned to a new 2016.
Basically, the advertising CPO's are comparable to the 2016 by $3,000 less all the way to equivalent. I'm looking at CPO's with under $60k.
I've checked Cars.com, eBay.com, KBb.com, Truecar.com & Toyota's CPO

My requirements for my next truck:

• Crew Cab
• 4x4
• Long Bed
• Bluetooth
• Backup camera
• Sr5 or TRD

My nice to haves are:

• White Exterior
  • Secondary: Silver, Grey, Gunmetal & Black
• Navigation
• Entune package
• Power heated mirrors

It seems that in my initial research, buying new is the best financial route.
I spoke with 10 CPO's & the local CarMax. Only one dealer let me know what they paid & gave me what they were willing to sell. He offered the paperwork to backup.

Any recommendations on negotiating for a CPO?
Websites with strategies?
Experiences?

One recommendation I received in looking at CPO's is to lean closer to vehicles with a low years of operation to mileage ratio. Citing lower mileage per year is someone who drives local, where high mileage per year is someone who putting a lot of additional wear and tear.
Also, avoiding commercial owners when checking CarFax.

Any and all help with your expertise is much appreciated!

Sincerely,
Another guy who drive his Taco to the end & ready for another