I checked spyderco.com, and they list VG-10 as the blade steel for both the FRN and all-stainless versions of the Delica, but Spyderco has used other steels in the past, such as AUS-6 and G-2 in my very old (1992) FRN Delica.
I wouldn't worry too much about AUS-6 in a Spyderco. In my experience, their heat treatments are very good, and the blade should perform well. I've always felt like I got my money's worth (or better) from both Spyderco and Benchmade.
BTW, you may want to shop around at places like
www.newgraham.com and
www.emergencyoptions.com or others. Prices may vary more than you expect, and if you want VG-10, I'm sure you can find it.
All my best,
Dirty Bob