Good luck with those estimates. Seems they will try as hard as they can to upselll you from the base model you seem to want.
I'll be keeping my eye on this thread, one day the wife and I might want to go that route. Right now I use the regular tub/shower combo in the second bathroom and she uses the walk in shower in the master bath. Neither of us uses a bathtub regularly, so for now, the walk in works when we can' get over the edge of a regular tub, as in after knee replacement surgery.