Help me Tweek my System, for less

I'd appreciate your help, in getting the most out of my system, I've got about 3k too spend on it, what can I do for little money to get the most. I will give you a run down of my system, and if you could help I'd appreciate it. Starting from the wall: Mit Z center, Sim Moon W-5 amp W/ Synergystic power chord, Balanced out w/ Nordost Quatro Fil's to Wadia 6i which is used as volume source I'm by-passing a pre-amp. and Nordost SPM speaker cables to B&W N 802's. All of the components are in a rack, between the speakers. My room measurements are 12.5 feet by 22 long with 8ft ceilings. Heavy throw rugs on the floor, with heavy Curtains on all windows and a couch with nothing in front of the Sound Stage. Like I said I've got about 3k to spend on tweeks and or upgrades, please help. My system sounds good, but every time I come home from my local High End audio store I'm disapointed in the sound quality.