I want to buy a legacy 1.8 lens for my NEX

I'm fine with either a 35, or 50mm lens. I'm looking for a decent older lens (with aperture and focus rings obviously) with a wide aperture of 1.8. I don't really know too much about older lenses, and what to look for, so recommendations would be very useful.

Thanks!

Also, I don't need a very high quality lens, just something to use to take pictures for my own enjoyment. I don't have any plans to make prints or anything. So my budget is about $150.

I maybe eventually plan to get the Sony OSS 50 1.8 lens, but I'm too impatient and want something now, at least to tide me over.