What will you buy in the way of fruit/veg even when it's really expensive?
For me it's lebanese cucumbers and grape tomatoes, as they're a staple of DS's diet. Lebanese cucumbers were almost $9/kg for a while last year, but I still bought them. Sometimes I'll pay $4.50 for a punnet of grape tomatoes.
One thing I won't pay top dollar for is avocados, even though I LOVE them, I can't bring myself to pay more than $3 for one. Silly I know