Spend more money on the amp or the pre-amp?

Let's say you have $800 total.  How much would you expect to spend on the Amp vs the Preamp? 50/50? 75/25?

What about if you have $400 total?  Does that change the ratio?

I would go on ebay and buy a nicely maintained Japanese receiver from the 1970s such as Sansui, Kenwood, Pioneer etc.
As an additional comment to my post above, for $800, I'd also highly consider one of those Chinese integrated tube amps.  Audio Space, Antique Sound Labs, Jolida, Prima Luna - there's a lot to choose from on the internet.  I'd also consider a custom tube integrated as well....I much prefer tubes over solid state, so I would get any of these over the Creek, Yamaha or any other SS integrated in this price range.
Yes, i agree with the suggestion to find a vintage Japanese integrated amp/preamp//tuner.   The higher power Pioneers my favorite.
But for $800 make sure that 40+ year old vintage piece has been truly refurbished not just cleaned 
Nakamichi CA5 < $300 and PA5 < $500, can't think of any integrated < $800 can beat that combo