It's wrong.

    3500 in -> go to parents house -> 1000 into bitcoin
                                   ->  100 into speculative coins on bull market, or making sorts in bear markets
                                   ->  300 into gold
                                   ->  600 to stocks with dividend growth
                                   ->  400 to real state or REITs
                                   ->  200 to speculative stocks
                                   ->  500 to your bank account (with some interest)
                                   ->  200 to cash, for those days you go out of your parents home
                                   ->  200 to presents for your parents

If your parents complain, give them the money of the presents, part from the bank account or from the speculative stuff, to silence them.

Repeat and reinvest benefits into non correlative actives.

Once you reach a balance of ((90 years - your age) x 12 months) * (3500 * N), maybe you can leave your parents home (not mandatory), and try to race with your yearly benefices, against the *real* inflation. N is a magic number, to cover the compound inflation during all those years, without penalizing too much the first years.

Maybe next year 3500/month is still ok, but in 30 years it won't.

If you're over 70's, do not follow this advice, take the 3500 and live la vida loca each month. Like in the "latin" song from the country that did never ever speak "latin".

Have a nice day.

Now seriously: The real important stuff when working with budgets, is to "see" the "estimate Vs real" thing.