The grounds there at HdS are going to be a lot nicer than Tohono Chul. HdS will be very polite. They'll laugh at you, but at least they won't do it to your face. They're classy like that.
They have a beautiful view to the west which is < Fronk voice > Faboolus< /Fronk voice > for a sunset ceremony.
Head inside afterwards and the patio is an awesome place to relax and run through the entire menu of appetizers and some good wine.
I'm thinking you could probably have grand time (rooms, ceremony... not sure if they'd charge to use the lawn, an evening on the patio for 4) for less than a grand. You may even be able to convince the bride you have some class.