Same here.
I've had to put up [WTB] notices and watch for [FS] posts here and over at Deskthority in order to get the sets I have now. It's taken three months, but I have Granite, Pulse, and Round 4 SPH on my keyboards, along with two sets of DSA Dolch that I bought directly from PMK (I'm guessing those finally sold out since they ran another GB over at MassDrop last week).
So while it is annoyingly difficult to acquire the sets that have passed us by, it is possible to get them.
Oh, and now's your chance to get in on the Round 5a GB. The amount of $$$ I've poured into that GB is almost embarrassing, but it has everything I love in terms of keycap design, so I just couldn't resist.