You don't want to get into a situation where a plumber or electrician has to tear apart your new kitchen if you build it on top of plumbing and wiring that is deficient. Give your kitchen the high-end look with stylish cabinet knobs and sink faucets. These cost little more than plain ones. Buy mid priced appliances except be careful when buying a dishwasher. You may want to spend a little more on this.
New colors cost far less than new architecture.
Add light with a sky light for a larger appearance. Use open shelves and glass cabinets. Edge the new countertops with cherry, maple or oak, to give a high-end look. Ceramic or Vinyl floors are the most durable choices. Stainless steel is durable, good looking and inexpensive.