mixing flavor vg pg

Hey, folks, I'm new to DIY mixing, and I have some questions. But first let me lay out the facts of my current situation (which I realise is not entirely ideal). My nicotine base is 30PG/70VG with 36mg/mL. I have a bottle of 30PG/70VG pre-mixed. (I realise I should buy these separate, but alas...

So i got this absurd dream of mine to mix 1l of juice, since my birthday is coming soon and i got my friends coming over and we will just vape it up so instead of paying 30€for 30ml of juice i would like to make my own juice since i calculated the costs it would only cost me 50-60€ to mix 1l of...