Let's see. $1200 for amp (used).
$800, 2641 kit parts + $400 finishing parts.
About 1:1
However, my speakers are diy and sound much more expensive than their total parts costs.
I have to say, the speaker upgrade was ---much--- more worthwhile, performance for dollar, than the amplifier.
Were I to do it over again, I'd put even more money, time, and effort into the speaker. Greatest gains to be acheived there, imo.