OK, can some one tell me what makes a custom set better than prebuilt? If it's stronger, then by what test? or just from your opinions? If it's better then in what aspects? And how much it gonna cost me?

I paid for a set of Campy Eurus or Mavic SSL for just 625, my LBS can true them, replace spokes without sending them in. So far I have not sent them in to get them fixed yet.