The most I ever paid for a guitar was $2600 for a Gibson L-7C. My second most expensive instrument purchase was my 8 String Chaparral Bass for $2000, a very nice discounted price on a custom order.
The L-7C is gone and the Chaparral value is a moot point since it is not for sale. My korina Vector may be holding its value.
My Sunburst has been where guitar money went in the last year. The guitar was bought reasonably. Some repairs added to what I have in it, but in my mind those are nothing more than the cost of use and wear. Thoughts of stainless steel frets one day are not connected to thoughts on the value of the guitar. This one will not be for sale any time soon.