Which of these power cords ?

You can certainly hear differences in power cables , if your equipment is up to allowing you to hear it.
Then it becomes a matter of how much difference you can hear. I have owned the Purist Audio Dominus Fluid power cord as well as the Dominus Fluid speaker cables and the Interconnects. They are the best cables that I have ever heard..IMO.
So, you have to decide how much better any are vs. what you have . You can only do this by trying them in your system

In review:

• Group A. thinks power cords make no difference
  
• Group B. think it's worth spending $800 or more on a power cord and they can make a big difference

Question is
- Will a $90 or a $150 power cord sound any better than the stock ones?

Wow so many choices thats your money its up to you.

You're not gonna get a straight answer on this topic around here, or anywhere for that matter. Buy a couple of those inexpensive ones you mentioned and see yourself. Hopefully you can return them if not satisfied.

Given your goals and short of making your own cords, which you should seriously consider, I think your best bang for the buck will be Cullen cables. On paper it looks like the Red Copper cable is a great value at $99/6ft, but if you can swing it there’s a lot more built into their Crossover cable at $199/6ft. These two cables seem to be more neutrally voiced, but if you’re looking for a little more warmth in your system the Gold series cable is $129/6ft. Cullen cables get great customer feedback and the prices are tough to beat. Hard to imagine you not getting a significant benefit from switching stock cords to these.

As a a dark horse option, I recently heard of Raven Audio that also seems to make high-value cables. Their Soniquil power cable is $169/6ft. and comes with Rhodium-plated connectors that you’d need to step up to the $199 Cullen Crossover to get. There’s obviously a lot more to it than the plugs, but to me it indicates good value and may also be worth a try as you never know which cable will synergize with your system and tastes. And both offer trial periods, so you can try both with little/no risk. That’s what I’d do. Anyway, hope this helps, and best of luck.