loot crafting

so i got dunk master darius primal udyr and pickpocket twitch. i thought ok don't have twitch and darius ill reroll. legendary skin might get a good skin. i reroll and i get infernal mord. what the hell riot what kind of system is this the more expensive you put in the better not get a 1820 rp skin then a 520 gg nice system [zombie-brand-mindblown]