Now that I finally now my real size I am starting to buy some nicer bras, which as you all know are quite pricey, so I'd like to make them last as long as possible.

I know how to wash them and all that, but have two general questions:
1. I know that you should not wear the same bra two days in a row, but how much rest does a bra need in-between? One day? Two days? Can you wear the same one every second or every third day etc. ?
2. Frequency of washing- assuming it's not an athletic bra and not a lot of sweating while wearing it has occurred, do you wash yours after every 2 or 3 or how many wears?

I can guess that some of this can be a matter of personal preference, but I am looking for a good starting point. Thanks!