We only replace items once they absolutely wear out - e.g. holes that cannot be repaired, thread bare, etc. If we grow out of something and the clothes are still good, we will donate them. Since my wife and I now both work from home and no longer have to travel for work, we have retired all need for the uniform (uncomfortable suites, shoes, ties, chemical goops for hair and body). We now dress down permanently. Think of the Steve Jobs Uniform - jeans and black t's - combo of short and long. That's about it for both of us, mixed in w/exercise clothes that we buy in high quality (e.g. 35$ running pants that last over 10 years or more).
We do not buy fashionable things but instead, classic, high quality, long wear neutrals that never go out of style.
We have saved thousands and no longer ponder this question. We get nervous if anyone invites us to something where we have to Dress Up other than jeans and t's as we have grown that much - for us in a good way. Mostly we opt no longer to go to those types events if our new persona won't fit. It usually means that the event is no longer a fit. Now, of course there may be outliers here like weddings, kids graduations, etc but again, we're not going to buy needless things to fit into someone else idea of what we should look like. As long as we are clean and comfortable, good enough.