The 300 series in no way compares to the 566, its about twice the knife as the 566. So keep that in mind, what area are you in so we can give advice on a B&M near you, and try it in the pocket before you buy it. Not just in the hand. Looking at used ones on the forum just look at weather its centered, scratched up, how far does the lock bar go over, normal stuff like that. Most of the ones sold on the exchange have been babied, your pretty much getting a new knife in most cases, check the seller's rep and feedback and glide right on by someone asking for you to pay gift or add paypal fee Ie net to me. If they can't figure out how to add that in their total price, well you get the picture.
North East Side of Dallas Metroplex. I buy a lot of used bike parts on another forum, so I'm pretty familiar with Paypal. Thanks for the advice!