I think the best advice I can give regarding knicks is to try as many as possible to get the best fit.
Unfortunately this usually means that you end up with a drawer full of knicks that are just 'OK' and only really use a few fave pairs.
I have found that synthetic chamois have washed better over time and that my cheaper knicks have worn badly. (lycra quality not so good or chamois stitching poor)
I've found a perfect supplier (for me anyway!) and they are called Giramondo. They are in glenroy/fawkner - just off the Hume and they supply the Aust track team and other racing clubs.
They use a chamois called 'monolith' and I love it!
Best of all they aren't too dear. ($70-80 for 8-10 panel bib knicks)
Also try bib knicks, i like these more than normal shorts. I find them more comfortable over rides of 3+hrs, even if they do make peeing harder!
$250 for knicks? I dunno. Maybe if I they were more comfortable than the Giramondo ones AND i had cash to burn!!! I can buy 3 pairs for that amount!
I find that my knicks get more wear and tear from washing than riding, and your most expensive pairs ALWAYS get pulls/tears etc asap.
Assos knicks will tear just as easily as cheaper ones, but you will be more upset!
I'm not bagging Assos, they probably set the benchmark for this stuff. It's just that they are a bit dear.
Hope this helps! (probably not hehe!)