Concrete base or slabs make sure you seal good under the base frame before you
erect the frame and glass so you don't get rain inside. OK try and make your budget bigger
mine is 6x10 and was glad I went for the bigger unit, auto windows are a god send..
i made some of my tables out of free pallets I am going to this winter make legs
for my water trays so I can use the space underneath, and going to consecrate on Sarracenia
so will be selling all my other plants, here is a image of my greenhouse it's a Elite.