Well it so happens that I have a Leitz 28mm f2.8 Elmarit R (3 cam version) lens sitting right here next to me. I also have a FA 31 Ltd sitting on my K5, and just for luck, I have a Contax Zeiss 28mm f2.8 Distagon T* over there sitting in my camera backpack. So, on to your questions.....
- How this lens compare to the legendary FA 31mm? - The 31 Ltd is an AF lens, while the Leica is manual focusing. That is a difference (especially for me since my eyesight is getting worse - even with coke bottle glasses). Build quality, the Leica is overbuilt, wonderful quality and handling. Image quality of both is excellent, along with coloring, rendering, sharpness, etc. Leica's optical engineers go for the Leica look. Now, the 31 Ltd, as I understand the pixie dust, was not designed to be the absolute sharpest, the absolutely best (which is very subjective) bokeh, etc., but was designed to produce very pleasing images. It's the total combination of all of the optical qualities of a lens. By all accounts - Pentax succeeded on that account.
- Is the price accurate? - You have not really provided enough information to answer this. Leica over the years has produced two major lines of lenses - the M and the R. Only the R can be converted to the K mount. The M mount cannot be converted to the K mount. Also, the R mount has been discontinued. Within each mount there are several versions of the lens from the older to the newer. The newer tend to command the higher prices (in terms of the R mount and the 28mm Elmarit design). The prices range from about $400 to ~$3000 (for the lens). Some versions of the R line are thought to be or considered to be better that others. Also, if you are looking at a Leica lens, you need to factor in a mount swap. There is not lens adapter available due to the closeness of the registration distance. Leitax.com (in Spain) charges about $100 for the mount hardware to swap it to a K mount. They will also do it for about $50 - if you want.
So, after having said all of that - my opinion. I have these three lenses, and my eyesight is not getting any better - for manual focusing. The drop dead simple answer is that I am going to keep the 31 Ltd. It is the perfect solution for me. It has the outstanding image quality and AF, its glued to my K5. The other two. This is a decision that I have come to over the last year or so. I am going to keep just one MF 28 and its going to be the Contax Zeiss. Why, its color rendering appeals to me a tad more than the Leica. Its almost a flip of the coin. I just have too many 28's that I am not using (I also have the K28/3.5 Shift). I am stumped as to what lens to take out shooting. So, I am reducing my choices and I need to make life simpler (plus - my A*300/f4 needs to be exchanged with the 60-250 since its AF (better with my eyesight) and I need to fund the swap - as instructed by the Chancellor of the Exchequer - my wife).
Going back to the Leitz lens - Leitz indicates one of the older models. 200€ appears to be a good price. What you need to do is to get the full description of the lens and see what recent sales of the same lens (with the same condition) go for on evil bay...
So, that is my take on the topic.