Tim...
I've played Shadow Creek and Cascata. Last time I played them (this past March), Shadow Creek was $500 and Cascata was $400.
I personally think if you can stomach the expense, Shadow Creek is worth playing. Some of the holes are pretty good and the experience is pretty neat.
Cascata is a trip. The clubhouse with the river running through it is cool. The course is okay. I don't really know if it is worth the price, but again if the cost doesn't bother you...check it out. It is fun golf with an over-the-top luxury experience, but the course isn't the greatest.
Both of the courses are over-priced, but I find everything in Vegas is by a factor of about 100%.
I think Paiute Wolf is worth the money...maybe $100ish per round.
And I haven't played Wolf Creek, but I'll bet anything Matt W. is correct and the course is a trip. However, I think it is really a ball-buster...so unless you are at least a mid-handcapper...beware. Matt, do you agree?