Are your friends mainstream food eaters or can you serve them ethnic food?
Do you have a grill?
My suggestions:
You can get away with "cheaper" dishes if you appear to have also splurged on other dishes so it's more that you choose the cheaper one because the food goes together, than that you were trying to cut back.
If you serve appetizers plus desert, it'll feel fancy still.
When your friends (as good guests will do) ask what they can bring over, ask them to bring over wine.
Have filler sides: homemade bread, soup, rice or beans, etc.
Make meat in the entree (if any) not be the star of the dish.
Cheap app: Try things like making hummus from scratch, or making your own bruschetta
My recent meal last Sat, one dinner pescetarian:
Appetizer: Homemade guacamole with chips. Bowl was basically licked clean and recipe requested.
Entree: Grilled pesto shrimp on a bed of jalapeno cilantro scallion lime rice.
(Rice the filler, shrimp the fancy bit. Buy it frozen on sale.)
Side dishes: Grilled veggies: Marinated eggplant, olive oil brushed zuchini & squash (very cheap); white bean salad (very cheap and totally demolished)
Drinks: Wine. They asked if they could bring over.
Desert: Fancy cupcakes. They asked if they could bring over.
Dinner a few weeks back:
Grilled chicken with a black bean mango cilantro lime salsa.
Same rice as above.
Desert: Homemade apple pie
Can't remember if we had an appetizer. Again, guest insisted on bringing the drinks over (a bottle of belgian beer, a bottle of wine).
Bonus, if you invite folks over often, then folks should either start returning the favor, or insisting that they pick up the check while out.
ETA:
skinnytaste.com for the salsa, rice, shrimp and grilled chicken recipe (we made it two ways, with hers and with a family teriyaki recipe)
smittenkitchen.com for hummus recipe
http://www.simplyrecipes.com/recipes/quick_and_easy_white_bean_salad/ for the white bean salad, but use cider vinegar for the wine vinegar, add a few minced garlic cloves and switch in fresh parsely for the spices
http://southernfood.about.com/od/grillfruitveggie/r/bl30627e.htm for the eggplant marinade from a fellow mustachian