Check some of the prices at local shops/caterers in your area. You can go in on the pretense of buying or just browsing. Some may have websites where you can check prices. Fudge here is sold by the pound - about $12.95. Dipped strawberries are $1.50 each. Most horsdevours (sp?) trays sell for $60-100 that serve 40-60 people which include 50-75 "bites".
In our state, you must have a liscense if you advertise in any way....website, business cards, ad in paper, flyers, which means you must have a 3-tier sink and be inspected by the local health department, so you may want to give this a second thought if you plan to advertise. If you do it by word-of-mouth, you don't have to have one.