Please, some of you seasoned guys need to keep in mind...
Usually a Hi-Max was flown under Part 103. Some were "fat" but if the builder kept things uncomplicated and light it could be a legal "ultralight."
Many ultralight pilots taught themselves to fly and all of the early aviation pioneers did. When a person with enough disposable income for flying starts telling someone who saved their lunch-money for years that there are not any affordable options for them to fly, I say "climb down from your high throne" and promote entry level aviation.
Here's my advice to the OP. Read and learn everything you can about how a plane flies, especially the book Stick and Rudder, by by Wolfgang Langewiesche. Hang out at the airport a little and just listen. Find a nearby ultralight hobby group and see if they know someone who has owned a Hi-Max or Mini-Max. Maybe they do and that pilot can help you make sure the plane is airworthy. Perhaps they may even test-fly it for you and help you work the bugs out if any exists. They can get it flying good before you try out the cockpit.
When I met him 25 years ago, my Sport DPE was the President of The Georgia Sport Flyers and owned a Mini-Max. It flew well on a Rotax 447 and I saw it pass through 3 owners' over the next decades. It never got bent or wrecked and taught 4 or 5 pilots to fly, a couple of them self taught.
The ultralight pilots I know who taught themselves to fly, were ALL RC Pilots for years! Before they ever sat in a running ultralight, they had learned enough flying R/C that they could explain things like why a plane can stall even in a vertical, nose-down dive, what overbanking tendency and adverse yaw were. They knew a lot about a 2-stroke engine and how to keep it form quitting.is an
What I am trying to say to the OP is...Get you a cheap, used, 40 size high-wing trainer and GET AN EXPERIENCED R/C'r to teach you to fly it. DO NOT TRY TO FLY IT YOURSELF. Real-Flight computer simulator is an option to speed up learning. Fly Microsoft Flightsim and skills will come.
Teaching yourself to fly is dangerous if you don't tippy-toe in. Go slow and DON'T GET DEAD! Good luck. I taught myself to fly in this $2500 Tierra. It had a single ignition (points)/dual carb 503 on it with a cogbelt prop drive. I put almost 150 hours on it and because of its ground handling characteristics, I feel a Pitts S-2 would be a piece of cake. If you look real closely at the vertical pipe under the horizontal stab, you can see the 12 Volt Black & Decker drill installed as an electric elevator trim