Frank,
My mechanic quotes a base price of $650.00 if nothing is wrong. However, owning an older airplane (1963 M20C with manual gear/flaps) there are things I personally want to have done at annual time. I usually budget $1500-2000 per annual to include those things I want done (new tires, heat ducts, etc.) In the 3 1/2 years of ownership my unexpected items have been a generator, starter, vacuum pump (only had 800 hours) and a prop cable. This year's annual was the highest yet because I had to have my exhaust sent off to be rebuilt. Labor, shipping and exhaust was around $2,000 with the rest of my annual costing $1,251 (included new main tires, intertubes and brake linings). The mechanic said it looked like the original exhaust (47 years old and 2200 hours TT). I spent almost $2000 on my van getting all of the 100,000 mile junk done. I got more value for my money on my airplane as my A&P charges a lower hourly rate than the car dealership mechanics.
When considering an airplane, be sure to consider your typical mission. My C model is ideal for my wife and I. Occasionally, we will load four people and baggage for a trip but 98 percent of the time it is just me and 1 other person. Beats the heck out of the hassels of flying the airlines...unless you get a thrill from the new TSA pat-downs! Our family motto is "Jones Airline...We fly on your mama's schedule!" My Mooney is a time multiplier since it allows me to cram more travel in a short time. With my job, I can't afford to be on the road 3 1/2 - 4 hours one-way especially when I can do the same trip in my Mooney in 1 hour. I file IFR everywhere I go and do it on steam gauges with a yoke mount Garmin 295 for cross reference. My typical trips are 1 hour in duration but will occasionally fly to Florida or Georgia (3-4 hours). On long trips my 180 hp will usually give me 140+ knots average ground speed. You can check my latest trips on Flightaware (tail number N6561U).
Just remember the more bells and whistles the more upkeep and operating expenses.