I buy valvoline full synthetic Dexron VI fluid at the local NAPA for $5.50 a quart. Not a bad price for full synthetic fluid. Other brands are cheaper yet. I think the best I can remember in recent years was around $3/quart of Dexron III tranny fluid that wasn't full synthetic. And that was probably 10 years ago. Look how much the price of engine oil has gone up in the same amount of time.