Sell DVDs on Ebay classifieds more expensive - is this legal?

So I came up with a cool way to make money.

It started like this:

I just wanted to sell some old stuff (old cell phone, Xbox etc.). Among other things, a video game for the Playstation 3. I bought it then for 1 euro at a flea market and now sold on Ebay classifieds for 10 euro.

I go to the flea market from time to time to buy any Playstation games there cheaper, and there's one of the games sold totally cheap. For example, the time I Tekken 7 for the PS4 what I would normally pay at Gamestop over 50 euro for 20 euro sold. So I thought I could now buy a whole load of video games and sell more expensive.

Now I ask myself

Is that even legal?

Am synonymous only 13, so only Ebay classifieds. Then I always meet with the buyers at the main station and sell those things there, because of my age, there were no problems so far.

Would that be legal?

You have the right to offer your goods at prices at any time, to which you then want to sell. The buyer is at liberty to accept the price or to act and / or to make the purchase.

Is that even legal?

No, because who buys goods to resell them, trades commercially. And that's the problem for a 13-year-old child.

What do your parents say about your trade? Did you talk to them about it?

Minors may sell their belongings only with the permission of their legal guardians.

Also on ebay classifieds you have to expect that ebay classifieds requires the written submission of the approval of your parents.

My parents allowed me, because I meet with the buyers at the main station (ie in public).

I would get written permission from my parents.

Then "only" the legal difficulty would be that you trade commercially. You do not get a trade license at the age of 13, nor can you find the judge for adolescents:

https://www.gewerbe-anmelden.info/gewerbeschein/minderjaehrige.html

Better keep in mind that you only sell your used things from the parents.

Would that really be necessary with the trade? And if so, would it be possible for it to go over my dad's name?

He will thank you, if he has to pay for your tax burden, in the social security is scrapped differently, your accounting needs to control, etc. Etc.

Of course, I would pay for the costs myself.

Child, your father would be classified differently in everything. That's not worth it!

Please stop dreaming.

So at thirteen you have an unbeatable advantage… You can do so every ten… Ten, because you are not punishable.

I hope good question does not turn me a rope out of it.

So do business too.

From 14 … So everything has to come over as a "sale of old things".

Something commercial must be registered. Then you have to pay taxes.

Never let it shine through as an acquisition.