Two weeks ago I refurbished an inherited PC (thanks Richard!) to become my desktop (1.6GHz P4, cd-burner, 64mb Geforce2 but only 256mb RAM). I bought 2x1gb DDR memory modules, with the rationale being that I'd better max the thing today, when this particular kind of memory is actually readily available. Did a quick bit of research as to compatibility, seemed fine. Thought I got a good deal at $170 for a new unopened HP-branded pack (when this seller's other items went for $200+). On insertion the box wouldn't even peep. Surprise, surprise.
I didn't realise at first that I had ordered buffered/registered+ecc rams. It turns out that most PC chipsets only deal with unbuffered/unregistered ram, and that I hadn't done my homework sufficiently well. Some Cursing ensued. The replacement pack cost me $270, because there's once again a shitload of fine print to consider when you buy large memory modules (this time it's "high-density"...I remember SIPP vs. SIMM and FPM vs. EDO, a nd single- vs. double-sided and...all this other PC crap).
So I put the Reg+ECC simms on ebay, hoping to recoup at least some of the loss.
Today the pack sold for $451, the money is already in my account and
the parcel is shipped.