OK I worked it out using the expenisive bread but bought at the bread store, as we normally do.
Arnold country white $1.39 loaf =16 slices, I counted them.
.10 per slice.
Using my Kraft singles bought on sale 3 pk for $5 /16 slices = $.10 slice
bread is large slices so you need 2 slices of cheese.
Grilled cheese is $.40
This is $.50 per lunch so now we are at $3.50 for a weeks worth of lunches.