A useful estimate begins with the route.
Before emailing, collect enough information to show the tub, the installation, and every constraint between the tub and the loading area.
Photograph
Take wide views, all reachable sides, the equipment area, gate, turns, stairs, and loading point.
Measure
Record the tub dimensions and the smallest clear opening on the route.
Confirm
State whether the tub is empty and who will make electrical and plumbing connections safe.
Define
List covers, steps, equipment, deck material, or other items you expect in the scope.
Start with the tub and the route out.
Share the tub type, measurements, photos, and access details. The scope should be clear before a date is set.