cpo benefits vs. 'pre-owned

[sprite007]

All,

Just wanted to know what the perks are for going cpo vs. just buying as pre-own.

Here is the situation:
Looking at a 08 or 09 x5 4.8i. For sake of arguement; say both have same specs/options.

09 x5 4.8 preown 48K
09 x5 4.8 cpo 52k (due to cpo warranty)

My quesiton is how beneficial is it to have a cpo warranty vs the 4yr /50,000 maintenance (whcih pretty much covers everything). With the $4k saved once an opt to extend the maintenance for another 2yr stretching it to 6 yr / 100,000K.

My question is what is so good about the cpo warranty when in theory after the orig 4 yr /50k maintenance expires you get a 'warranty' contract, which specifies that a lot of things are not covered and each visit cost $50...

just wanted to see what consensus is on this argument.