Interesting set. It looks like you're not interested in maintaining a particular/consistent spot progression; if I'm wrong and that is of interest, then methinks your spot pattern selection needs some tweaks.
As for what's in front of me, I like 1-100 and the 5k. While I like how the 500 looks on my monitor, I'm afraid that the blurple and blue offer little contrast when put next to each other(I have the color samples in hand - they're much closer together than they appear on screen, to my eyes), and the black isn't a whole lot better. I'm also not a big fan of the 1k, but that's just personal preference...I don't care for the spot color selections there.
The labels...I don't care for the numbers on the 25/100. I like how the 5000 looks, but I don't like that numeral style on the 1/5 (they look too plain), and the text above the number on the 5k starts to crowd the number itself. The most visually interesting are the 500/1k, but this is a case where form has taken over function. Someone could *easily* mistake the 500 for a 5 if they weren't careful. I'd have significant reservations about mixing numerals with text to make up the whole denomination, save for something like 1k or 5k with the two characters right next to each other...and even then, I'm not a huge fan.
Looking forward to how this set develops!