Food / Best place/way in Poland to buy groceries in bulk? [6]

Hello! I am new to this place, lived in Poland for a year. I am wondering where it is best(cheapest) to buy groceries (stuff for the pantry) in bulk. Need to save some cash the upcoming year. Tried a few different places this last year, carrefour, biedronka, lidl, tesco etc. I live in Gdansk, and do not mind buying stuff online. I eat a lot of vegan/vegitarian food so if anyone has any tips for vegan food in Poland I would love to hear that as well.