I've also come across this issue. My girlfriend and I were looking for places this week and we were each shown different prices for the same place on the same days. She was consistently being shown a lower price. A couple details worth noting;
I've used air bnb several times, she's never used it.
I was searching from my computer in Kansas City, she was searching from LA. We were looking for places in San Diego. Maybe proximity to destination makes a difference? (reaching, I know)
We were searching simultaneously and looking at the same places at literally the same time.
Really not sure if any of those things made any difference (they shouldn't, right?), but I'm stumped as to what could be happening. Any ideas?