A good rule of thumb: the bigger the greenery, the more green you have to spend. You can get a little teacup-sized succulent for as little as two bucks, but a fully developed fiddle leaf fig tree will set you back more than $100. A good mid-sized starter plant, such as a pothos or dieffenbachia, will probably run you somewhere in the neighborhood of $10 to $20 depending on the size and where you buy it.