The second hand market is filled with great audio gear. For example, last week I bought a high end Yamaha amplifier (DSP-A1, 5x 115W RMS) for only 18€ on eBay and just had to clean the volume potentiometer (I used this technique)!
This time I purchased the exceptional B&W DM-602 S3 speakers (on eBay as well) for 91€ with two defective tweeters. In good condition, these speakers sell for 200 to 300€ and replacement tweeters cost 75€ plus shipping so I guessed 91€ was a regular deal at worse.
First thing I did when I got my hands on them was to detach the tweeters: remove the woofer, the tweeter can be removed from the inside by twisting it. As expected, both tweeters were burnt and read 'open circuit' when measuring the resistance at the terminals.