I'm not really sure what the objective of this post is as it seems misleading.
WTB would indicate you 'want to buy'?
It seems like you have this part in possession and wish to sell it?
Anyway, the core shown for sale in the link above is a quality standard replacement not upgrade.
As mentioned, a turbo that's only oil cooled is not desirable!
Starion parts that 'are' in demand and would fetch good prices are LSD's, rust free body parts including scooped bonnet,
front and rear spoilers, suspension parts, certain electrics and upgrades in later models such as 5 stud and widebody wheels.
I hope that sheds some light regarding buying & selling these parts.
88 GSR-VR Widebody 2.6L
87 GSR-VR 12V Dash 2.0L