Baked Mac N' Cheese (with Ham)

I was trying to think of a way to use that 7lb ham that we bought last week, and who doesn't like Mac N' Cheese? This recipe adapted from a Taste of Home cookbook turned out to be delicious, but it did make a lot of food. We ended up saving half of it in the freezer for a time when I don't feel like cooking. I'm sure you could make a half recipe in a smaller pan.
I think this cost about $5 for all the ingredients (at Aldi), but it made 4 meals (dinner and leftovers for lunch, twice) so it would be $1.25 for each meal. Two people definitely couldn't eat out for that little!

4 cups uncooked elbow macaroni
dried chopped onion (to taste)
3/4 c butter, divided
6 Tbl flour
4 1/2 c milk
4 c shredded sharp cheddar (or white cheddar)
1 tsp mustard
1 1/2 tsp salt
1/4 tsp pepper
3/4 c cracker crumbs
optional: chopped ham

• Cook macaroni
• Meanwhile, saute onion in 1/2 c butter. Add flour, whisk until blended. Add milk. Bring to boil; cook and stir 2 minutes  or until thickened. Stir in cheese, mustard, salt, and pepper until smooth.
• Drain macaroni and add to sauce. Add ham. Stir until coated. 
• Transfer to greased 13x9 dish. Melt remaining 1/4 c butter and toss with bread crumbs. Sprinkle over macaroni mixture.
• Bake, uncovered, at 350 for 30 minutes or until heated through