You are right to look at the costs.
I believe your fuel will be about 15-20% more (on cross countries, you may not be able to control the price of fuel).
You need to add insurance. For two students/low time, will be in the area of $1,000/year.
You are banking on the engine going to TBO, and just building a reserve. The biggest myth in piston aircraft is "time to TBO". Some others on the Forum can speak to that. Gee, I bought a plane (two months after an Annual with 570 on the engine and comp's in the 70's) that lasted all of two hours before having to spend $14,000 to have it topped. Don't buy if you can't afford to rebuild the engine from day one.
I believe you may be low on "minor repairs". Owners know that anything that breaks is $500 or more, and with labor, it will come to the "aviation standard" $1,000.
Lastly, don't think someone will pay you what you paid for the plane if you sell it 1 to 2 years later. Your use will depreciate the plane more than the $1,000 you set aside for engine depreciation.
I own two planes, fly a lot, and know that beyond a doubt I could save money by renting. I make good money, and am willing to spend over $20,000/year just to have my own. You and your wife will have your hands full learning to fly. Adding the purchase, maintenance, and hassles of ownership may not be the best for you at this time.
Best of luck in whatever you decide. Mike.
