Physical attraction is obviously important and necessary, otherwise you will be with that person out of pity (and this almost happened with me). Now if you like someone because of their money... I mean do whatever you want.
And now you mentioned it, once I was with a guy who I found hot, we had amazing sex and he also had money, but something wasn't right and we didn't go through.
You don't know what you want till you find it, and once you find it, please never let it go (like I did).
No, the amount of straight guys/girls I know who just sleep with a guy because he/she is hot.
But in gay society there is a more transparent hook up culture. Plenty of gays don't fit into that culture but of course if you to a messy gay club that's all you'll see and it's a common stereotype.