Good question... the answers would be in your business plan.
Some one-time start-up costs to consider (office expenses):
Computers, printer/copier, cash register, coffee brewer and decanters, stir stick dispenser, cake stands (for samples and displays), microwave, safe, power tools and replacement batteries for cordless equipment, scissors, tape dispensers, staplers, soft drink vending machine(s), vacuum, time clock, signage (plus sign painter labor & installation), neon "open" signs, furniture (conference table, chairs, cubical walls, office desk, file cabinets, bookshelves, displays, etc.), telephones and equipment, cordless headsets, TV, digital picture frames, lockers, display cases, countertops, video security system, trash bins, wastebaskets, styrofoam dummies (for displays), surge protectors, clipboards, calculators, register corporation fees, business license application fee and 1st time gross license fee, initial accountant, consultant, and attorney fees.
Freezer, cooler, airbrushes (hoses, hangers, fittings, compressors), fans, glue gun, pencil sharpener, wire cutters, pliers, mop, bucket, enclosed cabinets, full size sheet pans, pan racks, spatulas, serrated knives, mixer, stainless steel work tables, industrial shelving, ergonomic stools, step stools, two or three-compartment sink with drainboards (plus faucet, spout, mounting kit, plumbing materials and installation), jig saw, turntables, decorating tubes/tips, pastry bags and couplers, mixing bowls, rubber mallet, claw hammer, foldaway platform truck, utility carts, personal handtruck, pallet jack, delivery vehicle, GPS system, angled tweezers, aprons, storage containers & lids, hack saw, shop trash containers with dolly and lid, power strips, start-up supply of separator plates and columns, silver cake plateaus (for rentals).
(product and materials inventory):
Copy paper, thermal paper rolls (for cash register), regular and decaf coffee, cups, lids, stir sticks, creamer, sugar, artificial sweetener, napkins, forks, plates, tissues, toilet tissue, paper towels, Handi Wipes towels, glue sticks, tape, staples, highlighters, pens, pencils, markers, dowel rods (plastic and wooden), soft drinks, bottled water, vacuum bags, pine cleaner, sanitizer, dish detergent, time cards and replacement ribbons (for time clock), airbrush color, paste color, business cards, brochures, parchment paper pan liners, assortment of cake toppers, toasting glasses, and cake knife & server boxed sets, gumpaste/gumpaste toppers and flowers, cardboard cake circles, cake drums, styrofoam dummies (for orders/rentals), lace, ribbons, dragees, foil leaves, poly-foil rolls, skewers, wax paper, plastic food wrap film, foodservice foil, bakery boxes, vinyl gloves, rack covers, quinns/decorettes/sprinkles, trash can liners, initial start-up supply of all ingredients.
Some reoccurring costs to consider:
Lease, credit card usage fee, telephone service, Yellow Pages ad, business cards and brochures, electricity usage, water usage, gas usage, car insurance, liability insurance, delivery driver, employee wages, payroll taxes, replacement inventory all operating supplies, product, and materials. (plus more endless possibilities not listed like trash removal, strip mall sign fees, snow removal, parking lot repair fees... the potential list can go on and on!)