What license to buy on themeforest?

Question

themeforest

I want to buy a ready-made html theme for a site on themeforest from envatomarket, the first version is regular license, the second one is 10 times more expensive than extended license. If I buy a theme, and then I myself or a programmer I hire, add the missing pages, code and various plugins, will a regular license be enough for me? I'm not going to sell this code to anyone later, I only use it for my website

Answer 1

let a = ['white', 'black'],
    b = ['red', 'green', 'black', 'white'];

let array = a.concat( b.filter( val => a.indexOf( val ) < 0 ) );

Answer 2

Well, first concat and then remove duplicates in a loop