Regardless of what you spend of them new or used, the CS.5 are an outstanding value, i've owned a pair and upgraded to the 22's. If they have a weeknesss it would be that they are fairly small and low to the ground and you may want to consider stands with them. Sound Anchor makes attractive and functional stands for them. All Thiels need a fair amount of power (200wpc into 4 ohms) and will reveal any weak point in your system system. You must have good electronics all the way around as well as good cables or they just will not sound great. Like the previous reviewer stated, MIT cables work well with them.
Good luck
Good luck