cost of blueprints
The prints (what you call blueprints) cost about 50 cents per square foot of paper. A set of drawings for a small house might have 10 sheets in it. Those sheets would probably be 24 x 36. So a set of prints would cost you about $30. Now if you're asking how much it would cost to design a small house, refer to the other answers. They are good ones. There are lots of variables here.