350 isn't bad. I paid 325 for a P6 with a some noticeable wear a few years ago. Nice pistol once you down-rev the hammer spring for easier DA.
I love my P6, but it would be nice to have more rounds as well. The P6 works flawlessly, but if you want to carry w/out a second magazine, P226 is the way to go.
I never had a P226, but I have never heard anyone complain about a 226.
Keep saving pennies. Buy both eventually.
I'm right about the metric system 3/4 of the time.