Here's my speculation based on the information we know.
Proof of speculation.
Exhibit A;
October 5, 2016. Phil Sspencer :"
http://www.gamespot.com/articles/xbox-head-phil-spencer-talks-scorpio-ps4-pro-4k-re/1100-6444198/"
"We'd looked at doing something that was higher performance this year, and I'd say the [PS4] Pro is about what we thought--with the GPU, CPU, memory that was here this year--that you could go do, and we decided that we wanted to do something different."
To me this says one thing, that any CPU,GPU, and Memory technology available in 2016 is not in Scorpio.
Exhibit B;
Jan 5, 2017 " The Picture'
"
http://wccftech.com/xbox-scorpio-amd-ryzen-vega/"
Exhibit C; Scorpio white paper
"4x L2 cache"
Based on these exhibits here's what i think will be in Scorpio.
CPU:
RyZen 8 cores Notebook based without SMT. SR5 @ 2.2 - 2.6Ghz
GPU:
Vega based 14mn "active" 54CU @ 900Mhz
Memory:
Power is why i chose GDDR5x 384-bit @ 3350Ghz 320GB/s
As far as cost Phil all ready said console level pricing or premium price.
Custom chips do not cost manufacturers hundreds of dollars, you must remember that these companies buy chips in bulk. Do you remember the leaked document from Microsoft that showed Xbox One SOC would cost exactly $26 and that's for all Technologies and Licensing of core Technologies. This SOC may cost MS only $30 - $40 Max. Example "A9 chip found inside of the iPhone 6s and 6s Plus. The estimate worked out to something in the range of $22 to $24, in line with an estimate provided by IHS iSuppli."
Scorpio start $399 and up