I've sold 2 FA35s on the marketplace. Both were in original boxes with all the stuff. One went for $365 and was nearly flawless. That was about 9 months ago. The other went for $300 and had a small flaw on the front element.
Forget about Pentax releasing a FF dSLR (not saying it'll never happen), there are still a lot of people using Film SLRs and the 35 is still a sought after lens. Some sellers are asking over $400 for it and I'd imagine there are one or two people who will pay it. I would never pay that but I don't care for the lens either.
If your intention here is just to get a feel of options, that's probably fine. If you are putting this out to collect potential buyers, you might want to check the rules about doing so.