Just got in touch with Stuart from CZC. You all know Stuart, right? 
Seems like CZC has the mags in stock as well. I'm picking up a couple at $35, plus a couple of other things, including a new HBI trigger. The mags might cost a couple more bucks over some other online store, but I prefer to give business to a forum supporter. And the combined shipping cost from the other items offset that cost anyway.
Cheers.
I agree. I like Grabagun and have always had good experiences with them, but if CZC has the same item I'd also rather give them the business, because they are on these forums, but even more so because when I first needed extra P-10C mags Stuart was a huge help (going out of his way to let me know that they had some in stock which weren't listed on their website, then contacting me right away to complete the transaction, and getting them in the mail in less than 24 hours). Great customer service.
So when I eventually purchase a HBI trigger (and probably one or two more magazines in the future), I hope I can get them from CZC.