Does upgrading you system have to be on a logarithmic curve?

Has anyone else noticed that the higher you go in sonic quality the more it cost to get an incremental increase in sonic quality. For example if you buy a 300 stereo from Walmart it sounds ok then you go a spend 3000 on one and the jump in sound quality is huge. Now to get the same percentage jump in sound quality you need to spend 9000 then 30000. So I am at the 30k+ threshold what do you have to spend to get the same incremental jump. This is more of a rhetorical question has anyone else experienced this.