This is really fustrating, especially with the return to even crazier prices for the BTO options. I happily paid the extra to boost my iMac graphics when I bought it, but that's not even an option now.
Want all SSD? Better have deep pockets and want a 27":
768GB Flash Storage [Add $1,300.00]
Let's be honest. Adding an SSD to your iMac was never really easy in the first place unless you liked looking at dust behind glass.