Interesting topic and a tough one to answer. While I have had many basses over the years, there have been a special few that have motivated and inspired me more than the others. Is it possible to put a value on that special magic that an instument has that brings out the best in us as players? This isn't to say that your dream rig has to be expensive, but remember that your amp is an important part of your signal chain and in that respect, your rig should be chosen for the tone and features that it provides. If you come accross a rig that rocks your world and brings out your best as a player, can you really say that it isn't worth the $250, $500, $1000 more than the other rigs that didn't quite cut it for you?