If you have already changed that much then your tune up will consist of spark plus, oil, filter, inspect suspension, bushings, top off fluids, and probably a couple other things.
Really, just get some spark plugs, change your oil and filter, check your suspension bushings (i.e. sway bar bushings, tie rod ends, etc), top off your fluids if needed, and grease your guides where your doors open. No point in paying the dealer to do this unless you don't have the time or a spark plug socket.
I usually grease the guides, WD40 the latches, and spray some graphite in the locks every fall.
What transmission do you have?