$69.95
I have bought two of these in the past from beverage elements and was completely satisfied.
http://www.amazon.com/dp/B00852CTYK/?tag=skimlinks_replacement-20
I use 1.5 qts water per pound of grain so that should give you 4.3 gallons to mash with and follow it up with 4.3 gallons for the sparge. This should give you right around 7 gallons of wort for a five gallon batch. You should get around 75 to 80% efficiency.