Am I considered to be a materialistic person?

Don't care much about blondes. Of course, you are materialistic to a degree. We are physical, you know, 'materialistic', in a manner of speaking, whatever else we might be. When it crosses certain line and becomes something which is hard or impossible to consider normal - that's another matter. Women are jealous and envious, no doubt. So are men. 

Monks are not materialistic.
All others are.
It is a matter of degree.

You may be paying more attention to your gear than your wife.
That's competition. Love the story about the San Jose techie
whose wife thought he had overdone it and while he was traveling
had goodwill make a pickup of all his stuff.

Buy her a toy that she may find replaces her need for you.
Like a Sybian. 

Monks are in deep denial of the human nature, they are materialistic too.

I don't love anything else I own but my stereo, it's always been like that, probably always will. I make no excuses, respectfully care not what others think about it. It's just me. 

Love my toys. I have three separate sound systems-one for vinyl, home theatre dolby atmos, and a small emotiva bas-x100 which I use with a pair of HD600 headphones and B&W 685 S2's and a thrift shop sony SACD 5 disc changer I found in a thrift shop. I have two Canon DSLR's with an assortment of lenses from 16-400 mm. 13 watches and six firearms. My records go back40-50 years that I bought back in the day and CD's when I got that bug back in the 80's. My best thriftshop find is a first edition Parlaphone mono pressing of Sgt. Peppers' Lonely Hearts Club Band with all the inserts which I have played twice, cleaned up and put away. Got it for $3.98. I am retired, live alone and am Prince of my domain. My cat Fatboy is King and he is rather disdainful of it all. But it all keeps me home at night as I would rather be home than anywhere else.