Cessna 150 seems to be the most affordable metal aircraft. What is the second most affordable?

Diamond DA 20 A1 Katana may be an inexpensive option, for 10 K more u can fly a newer plane than a Cessna 150.
But resale may be difficult.


Advantages

It can take MOGAS with out ethanol.
It may be difficult to get MOGAS with out ethanol in the future

Disadvantages

It is a composit airplane, do'nt know the life of the composit airplanes.

resale may be difficult.

Comparison between Cessna 150 & Diamond DA 20 A1 Katana


Good Cessna 150 Costs around 15,000 +-
Diamond DA 20 A1 Katana costs around 28,000+-

Cessna 150 has Continental Engine 0-200, overhaul is cheaper costs around 6,000. TBO is 1800 hrs

Diamond DA 20 A1 Katana has a Rotax engine costs about 10,000 to overhaul. TBO is 1500 hrs

New Continental 0-200 engine costs 20,000
New Certified Rotax engine costs around 25,000.

every mechanic can overhaul 0-200 continental.

difficult to find a mechanic for rotax engine.

Probably a Piper PA28, with the 140 being the cheapest. But just like you should also consider a C172 over the 150/152, you'd also want to consider the PA28-160/161, 180/181 also.

Its not really about the aircraft, but how u fly.
If u flew a 150 around at 100kts, u would be pushing it reliability wise, but if u flew a 172 at 105kts, its nothing.
Both aircraft r going to use about 7-8gph at those speeds, but the 172 is going to be quite a bit more reliable, & since the larger engines have longer TBO's, its worth moving up to a 17X series.
Well, it wouldnt really be moving up, since they r available at the same price.
The Mooney M20 is also an aircraft u can acquire for under $50,000, which would be comparable.
It has the reliable O-360, & it is small & very very aerodynamic, so it gets about 120kts out of 6gph & 175kts at 9gph. The only thing is that u need to go get is a few hours of complex training to fly it.
There r so many that could compete, youre going to get all sorts of different recommendations from any pilot u talk to. Just ask around & see what everyone says.

First off, I would suggest buying yourself a subscription to Plane&Pilot mag. They have tons of great articles about just what you are talking about. looking through a few old issues I found 3 issues that dealt with cheap/affordable planes. There is a list in one of the mags of 10 NEW planes under 100K. Email me if you want the list.

When checking out the affordability of an aircraft, a person must consider what it will cost to fix if something breaks, and what will the parts availabilty be.
These questions can largely be answered by: How many examples of this craft are flying today?
Answer: 13,843 Cessna 150s, 9,973 Cherokee 140s, 150s, 151s, 160s, and 161s.
Take your pick.

I have seen high time 150 is for as low as 5,000. Do not get hung up on this all metal stuff. I bought a Cessna 120 a few years back, with 600 hrs & a fresh top end, for 8 grand. It was one of the most fun aircraft I ever owned, but living in Northern Minnesota I enjoy low & slow, grass strips & skis in the winter. I agree with the gentleman about the Tomahawk. I flew one about ten years ago & any cross wind landing was scary, the plane was very flimsy. Most any FBO is going to have an old Trade A Plane laying around that u can look at & get a real good idea of what aircraft r selling for. Get yourself some tail wheel time, it opens up a new arena of affordable, fun & safe aircraft.

I would not like to see you get a Piper Tomahawk, and I am not sure about the Beech Skipper. They are cheap, but the Tomahawk has severe CG problems and is a known killer. Last I heard, the FAA pulled it in for re-certification the problem was so bad. As for homebuilts, that is probably a Ford versus Chevrolet type thing, but I am not comfortable with them. One man is opinion.

Cherokee 140, perhaps. Or a C-140, or a Luscombe. Or an Ercoupe.

You said ''affordable.'' That might mean just a beater, or one with a history of damage or neglect. In the long run, none of those may be cheapest. If you'd consider Experimentals, u can get much-newer machinery. Look at the LSAs (if u want ready-to-fly) or at used kit-built airplanes from Zenith or Czech Aircraft Works or Murphy Aircraft, or Monnett (Sonex). They're all good. In fact, u probably wo not go wrong building a kit from one of those four, & by the time u fly it, u will know what you're dealing with. You can build a brand-new Sonex, for instance, with an AeroVee engine, for under 25 large. Brand new. Takes about a year of weekends, if you're careful, but not too educated.