I usually have 4 everyday bras ( currently 2 white, 1 black, 1 beige) and two special ( coloured ) bras ( 1 red, 1 purple ). Due to sports I have 6 compression bras, but they are in the sports drawer and not considered lingerie. I machine wash on gentle and hang to dry. I don't think much about the bras, but every year after Christmas (Jan/ Feb) I audit my underwear thoroughly.
This year was a big overhaul, 4 new bras ( the coloured ones were all in good shape) including a fitting which resulted in a different size (32D). 6 new pairs of smalls, and 2 new half slips ( white, and black).
BTW, 2 people who have known me a long time, asked me if I had lost weight recently. My weight has been pretty much the same for the last 25 years, but I have noticed that since getting the new bras ( smaller band, bigger cup) the 'girls ' are higher, and front and centre, and my waist is more defined.