I think her numbers might be correct. You have four main cost-factors:
Condoms
D-Cell Batteries (most of her encounters are solo)
Liquor (for when they are not)
Viagra (he's gonna need an "assist")
Paper bags (2 per encounter)
Add all of this up and it could very well cost this particular person a grand a year or even more.
D'Oh!
Ha!
You know, you're exactly right. And if I could be so bold as to suggest something else . . .we both forgot to factor in the cost of the occasional gigolo or two. Not the Barney Frank "Hot Bottom" type, of course. Although, who knows? She might be the type who likes to strap on a tool belt once in a while.