Is there a big difference?

So i found a cheap rx 6900 xt Aorus model (515 usd) and since i was originally going to buy a 7900 xt Sapphire Pulse model (750 usd) i would like to know, what would you do? Is it worth going for the 7900 xt for an extra 235 usd? should i wait for the 9000 series?