How much will it cost for a 125 gallon tank with the filteration systems and aerators for largemouth bass bluegills yellow perch ad crappies?

A large mouth Bass gets to around 30 inches long and weighs up to 22 lbs and could make a meal of the other species you are intending to keep, so a very large tank would be essential with plenty of hiding places for the others species to hide in. A yellow Perch (or Redfin) grows to around 21 inches and about 5 lbs. A Bluegill is considerably smaller at around 16 inches and about 2 or 3 lbs. Crappies grow to 21 inches or so and weigh in at around 5 lbs. too. So if you wish to keep one of all the species you mentioned, and have them survive for any length of time, you will need more like a minimum of a 500 gallon tank. That would cost you several thousand dollars.