Under $150 became my self-imposed limit from the moment one in this hobby. It worked, better and better IEMs (like Trio to most, and AS24 for me) and DACs nowadays.
This hobby can be a bit easy if to realize that ultimate/perfect sound reproduction is hardly possible, at least due to current limitations of recordings that are done or reduced to two channrls - just two points of a three-dimensional space. Then good transducers attempt to reconstruct 3-D out of the reduction of recordings, and there can be different renderings - not ultimare or perfect but very much enjoyable at the given moment - that what life is about
P. S. For the "kilobuck" debate - the enjoyment is the difference between desired and achieved, and it is a dangerous illusion of just getting "one good one", there will be always cravings for more hurting either wallet or mental state, causing rage, etc...
I can nominally afford kilobucks by disposable income, but I have learned previously: hobby is a hobby - know your safe limits and enjoy responsibly