A good $8,000 amp will sound much better than a good $800 amp, that’s for sure. Jaw dropping? Only if you were clever/lucky enough to choose an amp that perfectly fits your setup.
Also bear in mind that for your jaw to drop you need 1/ To be sophisticated enough to appreciate a high quality sound reproduction. 2/ To be able to build a coherent setup/room system to give a hi-end amp a chance to show you its’ class.
Otherwise you can buy a $30,000 amp, plonk it on your hi-fi rack, and it will perform to 30% of its capability. Just like a $3,000 amp. So many people have done exactly that and claimed that there’s no difference.