It's going to be real hard to put on that kind of weight on a tight budget. You need CALORIES. LOTS of them.

Cheap Calories/Protein

1.)Eat a PB&J every night before bed. Use wheat bread. That will cost you about $6.00 for a weeks supply. It's going to get old real fast so make sure you alternate your flavors of jelly.

2.)Boiled eggs are rich in protein. A carton of eggs will cost roughly $3. I used to eat 5 every morning. Beware... your farts will be deadly.

3.)Water. Drink it. A lot of it. All day.

That's about all I got for ya. Eat eat eat! If you decide to get weight gainer powder, I recommend mixing it with water. Sure, the extra calories milk provides is great (not to mention makes it taste better) but milk is hard to digest and the body will be unable to absorb all the calories... thus meaning you are wasting powder.

Oh, and lift HEAVY. Less reps, more weight. Follow it up with some creatine and protein!

Good luck dude.