There's nothing really special about the MU ships. Wow! My Assault Cruiser looks like a Starcrusier - and it's using a Skin I bought nearly 2 years ago, too! Oh boy!
The Wells/Korath are far more unique, and they'll probably go for the same Exchange prices the Tholian ships bring.
Hence the IF and "we'll know soon enough" part of my post. We haven't had any leaks on Stats or any special abilities of the Time ships yet so until we know how they are special, they may not do any better than the Mirror universe vessels.