Are Room 17 and Six Foot Five that rare now??
That is a really good question. I think I can answer that question. Well, at least I can answer it from my own perspective.
Is the Room17 that rare? There are a number of them out there (668 according to Portfolio52). Heck, I have 8 of them. (Obscene, I know. But you all know I am crazy). I even have a Patreon backer one that is also signed. However, even as a very early Patreon backer of Lorenzo, we did not get low numbers (My signed deck is #657). Lorenzo wanted to get us low numbers, but they shipped him higher numbers. I don't know how Lorenzo managed to get a few low numbers, but he did for the contest. So, yeah, that is a rarity among Room17 decks. I guess it just depends though if having a low number is your thing. I personally do like low numbers, when I can manage it. I think it is also cool that this is actually a prize from solving the puzzle. That said, it would be really hard for me to put a price on it. I guess it just depends on the seller and potential buyers.
Next up is the Six Foot Five. The main issue of Six Foot Five decks was 250. Again, crazy me = 5 of them. That said, the Artist Proof I don't have. I don't know how many were issued, but it is reasonable to assume it is much smaller than 250, and those already command a healthy price. Then you get to the gilded. Again, crazy me = 0. What? Yeah it happens. This one had only 16 issued. I have rarer issues of KWP, but only a few. How much is it worth? $10 more than the regular issue Six Foot Five decks for the gilding?

Probably more. It all comes down to how much you want them.
For me, I already have a number of the standard issues and a signed one in the case of the Room17 that has the already sentimental value to me of being my Patreon reward deck (which I admit has value only to me), so I am personally not interested.
Are they rare? I would say YES! because these are an order of magnitude rarer than the ordinary releases. How much that adds to the value over a standard issue I don't know.