scaredy –
You’re one of my favorite folks on this board. I like FLU’s idea of getting a tape recording of your wife saying to go for it. That’s your cover if/when she changes her mind. She’s obviously intelligent – she got through med school… She may not regret this decision the way so many of the Piggs assume will happen. (And I think JP, CAR, and myself tend to blow the stereotype of how women react only on emotion.)
I like outtamojo’s suggestion to plan for zombie defense.
The money you are putting as a downpayment – do you get $200/month return on it? That’s the return you’ll be getting if you buy this – since you’ll be spending $200 less per month. That’s before any tax advantages that may or may not happen.
And – if this ends up causing marital discord in the future – there’s always the casita. (So make sure you address the zombie defense issues of the casita as well as the main house.)