I feel my thoughts are still evolving on something like how much would I spend, but for now, I can't see myself ever spending over AUD$10,000 as it is just too large a psychological hurdle for me to clear.
And despite nominating AUD$10,000 as a max limit, that doesn't mean I will get anywhere near that.
My most expensive complete bike purchase was AUD$1,700, but I have just built up a Surly Troll frameset into a complete bike and the total cost there would be close to AUD$3,000(In Australia a stock standard Surly Troll retails for AUD$2,400), but I acquired the various parts over a two year+ period.
In all likelihood, unless I buy an e-bike or a Surly Big Dummy, I probably won't ever spend more than AUD$3,000 for an off the shelf bike.