Best bang-for-buck purchase you have made?

SET EL84 amp for $26 fully tubed with GE tubes. One of best sounding amp I have heard ( Jadis SE-300b is more romantic but not in terms of dynamic and the price tag.) Compared with Sun Audio SV3 on JBL horn system and it blewed the Sun Audio away in terms of clarity and bass response. This little guy with no feed back really brings the music out of the speakers. For my second setup, it matched perfectly with Jensen TF-3 and Dynaco PAS-3 modified and DIY silver interconnects and speaker cables.

Novus plastic cleaner for about $4.00 and a microfiber polishing cloth from Wal-Mart for $2.00. Use on CD's.

Denon DL103R. An outstanding cartridge for around $200. Not available in the US, but if you are very good at researching sources, you can get them.

The other great bang-for-buck item I think is Lowther speakers. If you can DIY a cabinet, they will give unbelieveable sound for under a grand. The clarity and coherence of Lowthers is incredible.

2 that I can recall.

Paradigm 3se mk III mini speakers- I bought them back in the mid 80s for ~$250 new. Great speakers for the price, I sold them quite a long time ago. I can still recall the great performance for the price.

Recent- Classe DR6 preamp bought here on the 'gon for $950. A near vintage piece with a wonderful phono stage. I outgrew my B&K Pro10MC and did not want a outboard phono preamp to make my system more complex than it is. It was an ideal solution.

16ft. pair of Acoustic Zen Satori speaker cables for $955 new. It might not sound cheap, but what you get for the money is a steal.