I was thinking of making a post about the best deal i made in allanw's "I do believe I got a good deal" thread
But decided i'd make a new thread instead. Don't want to hyjack his thread.
So here's a thread were we can all post our best deals everFirst up of course is allanw, see thread -
https://www.eevblog.com/forum/index.php?topic=1709.0My story is as follows
Best/most interesting deal i ever did was many many years ago, i found some old OKI plasma display modules (colordepth of 4 shades of orange) in a surplus shop for NZ$9.50 each (around US$6), i got a 2 to play around with and try to build an interface to a VGA port so i could use them in my carpc. (This was like 1994 or something around there)
Here's a pic of the back of one of these plasma displays

After i tracked down the datasheet from Oki I managed to get an interface working pretty well with a few 74hc chips and some analog electronics to get the Red VGA signal to a 2bit digital one.
A few years later while searching for the datasheet again i came across a forum post of someone wanting the exact display i had. These displays had been in brand new condition when i got them, still in their polystyrene packing and plastic protective film over the screen. I sent off a few emails to the guy and he said he still wanted them.
Not really knowing what they were worth i just said i'd sell them for US$100 each. Seemed like a pretty good profit from $6. He then asked how many i had

So i went to surplus shop again, (this was a few years after i got the first two) they still had 6 of them left for US$6. Needless to say, bought them all and sold them all for US$100 each

I was pretty happy with that and bought a proper 7" vga lcd for my carpc with the profit.
However i felt a little guilty making so much profit (i was only 15 or so at the time, it seemed like a huge amount of profit to make). Around 4 years ago from today (im 29 now, so 10 years later) i was googling and just thought i'd google the displays again, see if i could find out anything about what they were used for.
Guess what i found, i came across a webpage of the guy i sold them to, he has been reselling them.
Apparently they are part of a huge old printing press that is still used. The display parts are worth US$4.5k new from the printing press company

Guy i sold them to has been reselling them for $1K to people with this printing machine.
So yeah, i could look back on it and wish i had charged more, but i dont, i made a really good profit from my costs and so is he

Guy i sold them too still has the webpage online, with pics of my old displays

i think they may infact be the same pics i sent him, they look familar

here -
http://www.jtgraphics.net/oki.htm