It is an issue. Money spent now is not money saved for later, so there has to be a balance. The question is, "How much is enough?" If one can hear the difference in components and if one likes music, then upgrading for decreasing benefits can always be lurking on the horizon. I struggle with the same issues and have only entry level Marantz Reference monoblocks, kimber cables, and PSB Bronzes.
I applaud you for holding it to the $5000 range and buying used gear.
My goal has been and is to hold the line on components, focus on the music(CD and Sacd),and continue to save for college/retirement. Looking at Audiogon every day does not make it easy.
"Nothing is enough for the person to whom enough is too little." Epicuris
Jndean

