Size of grow room for 2 plants

I was thinking of buying a grow tent in order to grow two plants at once. I was wondering what a good size tent would be if I want good yields and plants about 5ft high after flowering. I plan on keeping a mother in a really small tent all by its self so I can keep it vegging and use it for clones to avoid buying seeds every grow. Any help and guidance on a good tent would be great not looking to spend over $200 for the tent.