Since you're posting this on 3FC, you're connected to the net - the Panera Website has pretty much nutritional info on all their items (the bread that comes with their soup or salad is a bit hard to exactly measure, depending on how big a "portion" you got).
I usually do the half and half, checking the nutritional info on the items to order to make sure I can fit it in my plan. Last week I did the portabello panini and garden vegetable soup for a very filling and affordable ~450 calories.
Oh yea, avoid even looking at the pastry display