I would really appreciate if somebody can explain this to me.

There are many altcoins, some of which might have low volume, there is a community behind it.

Each coin/token holder can dramatically effect the price of the coin with each buy or sell.

If you are lucky enough you might end up becoming a whale for such coin/token.

I've noticed when:

I buy(depending on the amount), the price than dramatically changes.
I sell(depending on the amount), the price than dramatically changes.

So for example. Let's say the coin/token price is $1 at the moment.

I sell a 1000 coin/tokens while it costs $1 per coin/token. That would give me 1000 x $1 = $1000.

After the sell, the price of the coin/token has fallen to $0.50 per coin/token. That means I influenced the price.

But what happens if I buy it back again?

So lets say I buy the 1000 coin/tokens again. Will that be 1000 x $0.50 = $500?

Because this would mean by simply dumping and immediately buying again, I would make $500 profit. Does this make sense?

What's is clear that the next person to buy after me will do so at $1.

So applying the same logic would mean, a coin/token holder that can influence the price could infinitely make profit buy dumping and buying again?

Any clarification will be appreciated.