How do you determine how much to spend on speakers

I just happened by here and wanted to reply to Appasionata. You seem to really like NHT. I had several of their models from 1998-2008, including the pair of super zeros from the late 1990s. If you like those, try the NHT classic 2s, which can be picked up used. I even have a pair I don't use. They aren't expensive by any means. And I guarantee you the Classic 2s are much, much better than the late 1990s Super Zeros.

Buy used, spend 1/2 on speakers

Speakers are the last item on the musical chain; however, the golden rule "garbage in and garbage out" is absolutely correct.
You cannot correct anything wrong to begin with.
For the last 30 years, I have listen to system sometimes cost more than a house (over 300,000) and sound like you want to it off in less than 15 minutes. At other times, I can listen to a system with no more than $5,000 altogether and enjoy every minute of it.
TRUST YOUR EARS, a system is a combination of all the components and if you want to listen to it for more and more; no listener fatigue and that is a good system.
Something happens to the allotment of the speakers.
Think about a system with a 100,000 speakers yet hook up to a $200 receiver; will you say this is a good system?
Go figure.

I didn't read this whole thread because I'm not a masochist. But I read Robert Harley's book and he advised spending 50% on speakers. I found myself unable to do that, because the speakers I liked didn't cost that much money, and my analog and digital front ends both ended up costing in the ballpark of my speakers. If I were to look at my current system breakdown, speakers have ended up being about 20-25% of total system cost. I would imagine a number of people shoot for 50%, but end up in a similar situation when they find that they don't want to shortchange the good equipment in their systems with bad equipment. I agree with Robertwolfee and others who have said this: "trust your ears." And don't spend more than you can comfortably afford at any given time.

I have never understood the relevance of the phrase "garbage in, garbage out" in these types of discussions. If a $1000 to $1500 integrated amp is producing "garbage out", then you were ripped off. The THD on a Yamaha a-s1000 integrated, which sells for around $1200 is less than 0.02%. The only thing that a more expensive amp might do is play louder. Louder, not cleaner.