How cheap can you go and still be happy with the sound?

I think you would be surprised at the incredible systems that some people can put together at a reasonable price. 

"Incredible" and "reasonable" are both relative terms.  

The best speakers I bought and enjoy are the JBL J216 speakers paid 40 bucks for them . At a Antique shop . I had speakers over 2 Grand could not compete with those. There efficient and sound fantastic tubes or solid state . Ant cheap tube intergraded amp will be fine . And a Rotel make excellent CD players for the money .

LOL@ the snobs.

I’ve owned three tube amps (I still own my first one) and the best sounding I ever owned were a pair of monoblocks that could be a bit unreliable so I replaced them, but they were the amps with the highest MSRP.

I own three preamps, and each successive preamp cost more than the last one and each one had sonic characteristics that were distinctly better than the one it replaced.

YMMV, but my experience has been that every increase in sonic performance that I have ever experienced has required an increase in expenditure. To me, that does not seem all that unreasonable.

Bose wave radio while washing my car in my garage. Better than nothing or accidentally getting an expensive piece of equipment wet. Happier than nothing. Kind of a trolling conversation though.