I invested a total of 750 euro in Fortnite. How many euro is my whole account worth! And where can I see how long I have my PC account?

PS: How much did esporters actually invest in Fortnite Account? More than me?!

There are already many who have spent even more, regardless of whether they are esports. As long as you don't have rare skins like Renegade Raider, OG Skull Trooper etc, you will hardly get anything for your account.