Concurrently testing 2 pricing schemes for the exact same service feels sketchy or unfair (to the customer) to me–especially if its a 2:1 ratio ($5 vs. $4.99 I can understand).
I'm sure it doesn't fall under "price discrimination" but it still doesn't feel right ... should I not feel that way?
If you're really against it, don't test two at the same time. Just double the price for new customers and see how that affects signups.
My gut feeling is that A/B pricing would be illegal because it's unfair: a part of the buyers have a discount the others don't even know about.
IANAL though :)
I believe as long as it's a different physical store, it's probably possible to set a different price.
My impression (that would need more research) is that having two different prices for the same product at the same time inside the same physical store or on a website would be problematic; otherwise it's probably ok.
I think I really need to make more research - A/B pricing would definitely be interesting.
I'm not sure which is more common (fixed price across the country like here in Uruguay or Argentina, or store-by-store variation like the US/Canada)