i think i qualify for this club.
let's see...
Helios 44m-4 as part of a 3 job lot. So broken down by item (lens and camera as an item each), this lens cost me $3.50
With the aperture pin pressed down permanently with a bit of surgery, and a quick dab here and there with isopropyl alcohol to loosen up the focus ring to reach infinity, the lens gives me images like this:
Super creamy bokeh!
and crispy lifelike renditions, even on a k100d
$20 for a M 50 1.4 k mount gives me this:
$12.5 for a dusty Takumar 135 2/5 non SMC version k mount with filigree fungus on the front glass around the edges gives me shots like this:
And at the same sale as the Takumar 135 (it was really both lenses for $25) for an Adaptall 300mm 5.6 (early version) gives me images like this:
Oh, and I should include the Pentax M 35-70 which I got with a k1000 for $2 (so $1 for lens, and $1 for body). Lens has some fungus, the filter is permanently stuck on the front, with a lightened streak across the filter glass, but it still performs (i think) with images like this: