Be afraid. Be very afraid. Be less afraid if you never go into the big room at the high end dealership. Everything will become much easier for you if you stay the heck out of there!
Learn to listen.
Learn to say No. if thats not a strong suit for you
or just listen to your significant other more often.
Depending on how deeply you wish to injure yourself, er, get into this economically draining & psychologically debilitating distraction, parading as a normal past time, keep in mind that everything makes a difference. Everything! The room. The Cabling. The rack. The incoming power. Your ears. Pets. Neighbors. But most of all it could well be your own ego that winds up driving you to the poor house.
Find your own sound quickly. For some its tubes, for others its solid state. Further put, its SET amps & High eff speakers, still others will opt for digital or analog throughout. This means going to showrooms. Do bare in mind the big room caveat. Self honesty here will pay dividends later on.
Great speakers can not fix upstream signal losses or problems.
Spending a lot is optional. Eg., ego. Spending wisely is better.
Mate speakers to the room, amps to speakers.
Putting money into room acoustical treatments is just about a must to reap the true benefits from your system.
The best barometer for how good a system is will be the width of the smile on your face, the amount of toe tapping going on while listening, and the difficulty you have with turning off your rig. When that becomes a routine, daily event, you are finished and should then seek out another hobby to master, and allow your present audio contrivance provide you the pleasure it should at that point, rather than allowing it to nag you for more time and money to be sunk into it.