Best bang for the buck

My speakers cost me close to $1000 in parts to build in 1989, and I've managed to build a system around them that I've loved for decades, and will very likely be with me for life.   Got my money's worth years ago.  

A lot of good deals over the years.  The best bang for the buck are the pair of dipole towers I bought used a few years ago for $100.  Still going strong as Left and Right fronts in a 7.1 system.  

Well shoot me but back in 1973 I got a,pair of Bose 901s  2 one year old,with stand and another lumber yard round block of wood.To raise the 901s to ear level...at the time the 901s were going for like $550 fair traded....no discounts back then plus taxs..I got them for $315....cash...I loved my 901s....so there....lol.Had them for years then they need 18 speakers replaced...they are now in Speaker Heaven. 

An Apple USB-C Dongle DAC for $8.

Recently that would be the Riverstone Audio  Stylus Gauge.   Excellent product for cheap.     Another product I think is a huge bang for the buck is Ned Clayton's SUT.   Great product , build and sound quality is high for the price