What's the most overrated or overpriced piece of equipment you own, have owned or come by?

Bondmanp, Cables are an area where a little research and basic DIY skill, together with the use of first-rate materials and a modest investment of time, produces VG to excellent results at reasonable prices. My current loom is

PCs: shielded 8awg .999 silver or Furutech Alpha 3 bulk cable with Furutech ends.

Speaker cables: shielded and grounded, teflon and silk insulated .999 stacked silver foils with 1.5 lbs. of silver therein.

ICs: shielded, grounded Parts ConneXion Connex/DH Labs BL-Ag balanced silver bulk IC cable with teflon dielectric and Neutric ends. 100+ ft. @ $16/stereo ft.

At the current commodity price for fine silver, the entire investment is perhaps $4K. Over the years I’ve wasted perhaps 5 times that in commercial cables that depreciated, and demoed some in the $10K range that don’t compare to the better DIY.

I try to believe that all purchasing decisions in audio should be considered at the margin of the greatest improvement for the least investment. There has always been something better to buy than expensive cables.

The $4K represents everything in the loom.  Materials for the speaker cables cost $750.

BTW, I'm not suggesting that cables are unimportant-- rather that this endeavor is accessible to the average DIYer with almost no knowledge of electronics.  Once understood you could hire a high school student or my sister-in-law to make cables...