For some people, they think that happiness is equal totes to having money.

On a meme, you might write "happiness = money", but it's not strictly correct.

The more money they have, the more happinessy they can getare.

To some extent, I do agree with this view.

Generally, using "do [verb]" instead of just "[verb]" is for emphasis (there's no distinction in meaning). But this in this sentence, the emphasis contradicts "to some extent".

Since money is the foundation for everythingon which society is built, you need money to lead a high-quality life.

What you wrote is correct from a language perspective, but it's illogical. I changed it to something I would normally expect to see.

For example, if you want to buy some designer clothes, you need enough money to cover the price.

If you want to improve yourself by learning something new, like dancing or somea musical instruments, and you want to gain this skill as soonefficiently as possible, the most effective way for you is to hire somea personal trainers.

Ordinarily, people only learn one musical instrument, so I guess that's affected how we speak. I'm uncomfortable with "as soon as possible" in this context, since the skills described are gradually learned over years, whereas "as soon as possible" indicates it will end at some point. (It's suitable for e.g. "I want to get married as soon as possible" because once you're married, that's it---it's complete. But learning to dance is not like this. [You could say "I want to *start* learning to dance as soon as possible."])

On top of that, money enables you canto travel with this money to broaden your horizon.

"you can travel with this money" sounds like you're going around the world with cash in a backpack.

For sSome people fromin rural areas in which, where living costs are low, they lead a simple life.

I don't think what you wrote is wrong, but it doesn't sound fluent.

They never think about something at a ridiculous priceextravagances, so they are quite satisfied with what they already possess and lead a blissfulsatisfying life even without moneywealth.

English just so happens to have a word that means "something at a ridiculous price".

"a blissful life" is over the top (we talk about "marital bliss", but not "bliss" when just discussing life's basic necessities); "without money" implies they have no money whatsoever (or almost no money), whereas "without wealth" implies they don't have a large amount of money.

But now, I have grown up and I know how hard it is to earn money, so I always targeseek out rock-bottom prices now.

"target" feels wrong here (I don't really know why). Already said "now" in "But now".

And I just want to earn a good salary but not to be seriousoverly rich.

"seriously rich" is also okay, but in the context, I feel it's better to emphasize having the drawbacks of having too much money with e.g. "overly rich" or "excessively rich".