500ft
It strikes me that you are over regulated by people who have no idea that one SEP is much like another.
I blame the blood sucking leaches that are draining society white (some call them Lawyers) who are making improper use of the law and forcing airworthiness authorities to legislate far beyond what common sense dictates.
If trained to a reasonable standard any PPL holder should having spent time reading the POH be able to get to grips with most SEP's albeit that some powerful aerobatic types are going to require a little more work.
However simple airmanship should tell a PPL holder with 50 hours in a C152 that he will need a fair deal of instruction to fly an Extra 300 NOT a bunch of restrictive regulations.
I see no aircraft in Mad Jocks list that require any more than a good look at the POH and a quick circuit with an instructor to get a competent PPL up to speed to fly.