I agree with the advice to borrow the spotter, spend money on Binos. The most important aspect of a western hunt is locating animals from afar, which means spending a lot more time behind binos. Once you locate a buck (which with quality binos will be easy to determine) then you switch to spotter to see if it's worth getting closer to. I'd venture to say that, if looking through a viper spotter vs a high quality spotter, if an animal looks "borderline" to you in one, it will look borderline in the other ( either way you are getting closer to verify). As you get into "range", whether you define that as 300 yards or 1,000 yards, that viper is still going to help you decide shoot or not.
Of course, if you will only be satisfied with a 190" buck, and assuming you are an EXPERT field judger of inches, then throw all of this information out the window. If you are literally adding up inches and will not click off the safety if the buck doesn't meet your mark, then you will need that high quality, high power, spotter (and a very sturdy tripod).
my advice, spend $1200-$1500 on binos and $300+ on tripod (personally I'm not very picky about the head).