Hey Matt -
Let me get your opinion, maybe it is hard to answer, maybe The Arista can change a bit over the months, but.......say the price difference was 10 bux for 100 sheets. Would you be just as happy to go with Arista, or would you buy the Ilford.? Again, this is RC Multi Contrast only.
Thank You
What are you using the paper for?
For contact proof sheets? It would be fine.
For learning? Probably that too, as long as you understand that next year when you go to buy more, it may very well have changed, so that will add to what you need to learn.
For doing smaller prints, when there is a possibility that you will want to step up to larger prints of your favourites, or to give as gifts some of the results - consider the Ilford paper.
It doesn't hurt to learn how to adapt to the differences between papers, but if your darkroom time is limited, or you are still developing at least a basic proficiency at printing, then minimizing the variables is a great idea.
If cost is really important, consider printing 5x7s instead of 8x10s (I cut 8x10 sheets into two 5"x7" sheets plus some useful scraps for test strips) with 8x10 being saved for "special" prints.