well I have NOT hunted antelope there, but have spent a bunch of time in WY , and seen a lot of them there, but mostly in winter time, so ranges change
However if your willing to hunt SD over WY, I might be able to get you a decent hunt there, could even add a deer (50/50 spilt of white tail and mule deer in area) IT would be more of a do it yourself hunt, than a fully guided one, to get the best price, BUT can also be a fully guided deal too, if thats what you prefer.
I used to hunt a few states a yr for many many yrs, and found some great places and deal to allow for more hunts, as my budget wasn't unlimited in any way! just saved up and worked all yr to have funds to take trips!
if your interested let me know, and I can PM you the info!