Suspicion CONFIRMED

I have a suspicion that my family is bias to my younger brother and I have another evidence of confirmation.

Whenever my bro decides to buy expensive stuff like Chanel, Gucci, Prada... or expensive stuff, whether online or physically shopping, he is left unchallenged... not stopped by my parents.

Now I have a valid request, that is to use my own money to buy a set of dumbbells and my friends have shown me a set of good dumbbells to my opinion and I like it. I have being working out using a set of 3 KG dumbbells and they are too light. I don't get any progress if I keep using it and I need a heavier weight. Getting a set of dumbbells is a more valid request then my bro's expensive and useless shopping and my request is for better health.

Since months ago, I brought up the request to buy the dumbbells, just to tell my parents for courtesy's sake. I could simply just buy a set without telling them. But time and time again, they keep withholding and delaying my request infinitely until as of late, I told them about my intentions to buy a set of dumbbells I thought I like. My parents immediately veto-ed and objected the dumbbells I wanted and they wanted to bring me during this Friday (Deepavali holiday) to go get their "variant". 

What is wrong for me to get what I want ? 

Why must my request be rejected only for them to impose their will on me for the better or the worse ?

Why does my bro get "free reign" while they (my parents) simply control, reject and veto my options which are far more legitimate and useful then whatever my bro gets (all his expensive, luxury goods).

Why is it so UNFAIR ?

Oh, and one thing, my bro joint in the fray and started criticizing my pick and stirred up more topic of debate, en-strangling my parents' view that my pick are not valid, swaying my parents to ensure that my pick would never get through.

Thus from this, it confirms my long standing suspicion that my parents side with my bro.