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

I have been convinced for a long time that a great preamp is the heart of a system. At $800, as others have said, I would go for an integrated, but at higher price points, I don't see a hard and fast rule. The days my preamp ratio is 45:55. Some years back- when I had my first truly great preamp, the ratio was more like 60:40. That preamp was a CJ 17LS2. 

I agree with looking for a good integrated with a $800 budget.  If you want new, I'd look at the Yamaha A-S801.  6 moons gave it a very good review.  You could probably find something better sonically in the used market, but the built-in DAC on the 801 appears impressive - so a great value.

If I was looking at separates for $800, I'd probably buy a used Haffler amp that's been moded by Musical Concepts.  That will probably leave around $200 left for a pre-amp.  Might be able to find a Musical Fidelity or Creek (or other) on ebay for that.

So many directions you could go...

+1 for lou’s comment .
A good Dyna Pas3 or one of its many clones is the best buy in all of audio.
Truth be told , a rational person(leaves me out) will never need more.

Also true the new Yamaha integrateds , even the lowest , are great sounding and great buys .

$800.00 get some very cheap stuff and pretend it sounds good.Good luck with that one!!