Ms. Chu needs to buy hot dogs and buns for the school picnic. She needs at least one hot dog and bun for each of the 40 students. Hot dogs come in packs of 6 hot dogs and cost $3.00 per pack. Buns come in packages of 8 buns and cost $2.00 per package. Ms. Chu currently has collected $25 to pay for the hot dogs and buns. How many more dollars are needed so that each student can have a hot dog with a bun?