If you don't mind Windows, lots and lots of cheaper options. But you already knew that.
Ultimately, though, my beef with their pricing is not really about this specific release which obviously uses cutting-edge components, but about Apple's general approach to pricing these upgrades. They'll happily sell you old tech with the same crazy markups. You can still buy a new 27" Intel iMac with 8GB of RAM and the option to upgrade to 16 for $200. That's just a normal 8GB DDR4 SODIMM, which you could instead order for $29, and it installs in about 15 seconds.
I get that businesses need margins to survive, but Apple's stinginess and customer unfriendly price structure with storage and memory has been going on for a long time and just really bothers me.
I like their products! Just let me spec it such that it deserves the "Pro" label without feeling like a chump.