[eddie1960]

what about the Rokinon 85 f1.4
there's been some pretty good work i've seen of it and it's an A lens so more functional. 275 and up under various names
not cheap but compared to some of the pentax pricing a steal
there are some taks on fleabay right now as well

[Just1MoreDave]

...For me, the FL difference is huge...

Sorry about turning a nice post into a sound bite, but this was my first thought when reading the thread title. The Limited series is a set of mostly unusual focal lengths. Just on that basis, it's hard to come up with lenses that look comparable individually. And focal length is important with prime lenses.

The lens I would have suggested a few years ago was the FA 35/2, which is why I bought one. The ratio of its price to the FA 31/1.8 is about the same now as it was then, but today's FA 35 price is just over the top for me. If you can get over that and the slightly altered field of view, it's an excellent substitute. They're even both FAs, so features are nearly identical, except the FA 31 has an official lens profile now.

[paperbag846]

replicate focal lengths on the cheap:

FA 31 --> K20 f2.8. Not really worth it, TBH. DA 21 would work. Or a zoom if you don't care about DOF. Sigma 30mm f1.4, but you don't replicate the focal length you would see on film. Better value, though. This one is pretty tough to replace.

If you are on a budget, consider just using a zoom. You aren't going to find anything cheap in the 20mm range that isn't a zoom. I suggest the DA 16-45 f4.

FA 43 --> A 28mm f2.8 (or f2 if you can swing it). Good lens for the money, exact same FOV.

FA 77 --> any 50mm f1.4. Almost the exact same FOV, sharpness stopped down close enough (at about f2.5 I don't really care) bokeh quality is good with both. About 80% of the quality for 25% of the price (FA version)... my idea of a good deal. 50 is much easier to use for general portraits on digital than 77mm is, which can be tricky (but rewarding).