Your question will elicit a wild array of responses as to what is necessary to spend to get "a good set up". Your comment about sitting down to figure out what is in your system and being shocked when you actually tally it up will resonate with a large number of people.
I'm betting that with a Bottlehead Foreplay preamp, a pair of Bottlehead amps, a DIYed DAC from someone like twistedpear, some DIY cables made from good recipes, and the Altec Model 19s I just picked up for speakers for a second system, and then a bunch of room treatments (and probably a decently large room), one could do extremely well (with a fabulous soundstage). One would not get the be-all-and-end-all of systems (probably lacking in lowest octave, maybe a bit less revealing than $100k of world-beater amps and speakers) but I'm betting it would get the job done admirably. That would probably set you back $3-4k depending on how much you spent on the DIY cables, DAC, and how you got your speakers. If you were willing to build full-range speakers off freely available plans on the web, you might do your speakers a bit cheaper.
Buying all of the above used would not cost any more than $4k I bet.
My main system has less than your number invested in it (assuming the less expensive of the two vinyl setups and using DAC as pre) and while I love it, I expect I could great sound for less outlay. I am in the process of putting a second system together for a country house, and am trying to see how cheaply I can get absolutely first-rate music reproduction. So far, the above-mentioned Model 19s are accompanied by temporary stand-ins for amp and CDP (EAR 859 amp and Sony SCD 777ES) but am thinking others (though the EAR 859 might be cheaper than the FP set-up now that I think about it), and a DIY DAC of some sort.
