A man I met through a business deal went to Oshkosh and wanted to get his kids into flying with a father son project but was discouraged by the cost of everything he saw. Then he saw the Legal Eagle and Legal Eagle XL. It is a true ultralight but solid welded aircraft tubing fuselage and standard wing construction. It flies like standard aircraft. Estimated cost to build was $3000. He ended up buying plans and materials, one for himself and one for each of his two son's. Looks like great fun and it's a true ultralight. He said the rear fuselage tubing is left uncovered to get enough drag to keep the speed low enough to qualify under the speed limit and it is well under the 254lbs so some addition of equipment can be done. I thought this might be of interest here.
Leonard Milholand's Better Half VW and Legal Eagel Ultralight!