Please describe "transmission place." Was it one of the national chains, or a local independent?
The national chains will always try to sell you a new transmission, or charge you a fortune to rebuild yours.
Why can't the dealer replace the pump only? You don't have to allow them to do things you don't want.
If the crank sensor is bad it should be replaced. The crank sensor can be tested to verify its condition. You don't have to guess about this.
Three transmissions in only 134K miles? That's not very good.
You didn't say, but have you checked the level of the transmission fluid?