Dude, you have GOT to go to Tucson. This is not optional. If you back down on this, you might as well just slice off your nuts and hand them over to her. The $200 is not a big deal in a two-lawyer household. The time is not a big deal (one weekend, two months from now). She's making it a big deal in order to bully you. She wants those nuts handed over in a bag; don't give them to her.
Nop had a good idea about the camping trip. But don't do it instead of the Tucson trip, do it IN ADDITION to the Tucson trip. Just give her adequate notice so she'll be prepared to "hold down the fort" for the weekend. What possible objection could she have? The answer should be revealing.
Obviously it's very important to her that you have no financial independence at all (and maybe no independence at all period, financial or otherwise). But seriously, so what? Sex is important to you - does she care? Of course not.
Tell her you'll skip the trip to Tucson if she'll agree to spend the weekend in bed with you having sex, instead. That should get a fun response.
