Conversation so far:
Where was Mike Piazza' childhood years spent?
Mike Piazza was born in Norristown, Pennsylvania
where else did Mike Piazza grow up in besides Norristown?
Mike Piazza grew up in Phoenixville, Pennsylvania
what is interesting about Mike Piazza's childhood?
When he was 12, Mike Piazza received personal instruction in his backyard batting cage from Ted Williams
What was the outcome of Mike Piazza's bat boy service?
what other training did Mike Piazza receive besides training from Ted Williams?
Vince Piazza threw hundreds of pitches nightly to his son Mike Piazza, clearing snow if necessary to practice his hitting and practicing on Christmas Eve.
What was Ted Williams's assessment of Mike Piazza?
The Hall of Famer praised Mike Piazza's talent, advised him not to let anyone change his swing, and autographed Piazza's copy of Williams' The Science of Hitting.
Did Ted Williams' praise inspire Mike Piazza to do better?
Mike Piazza shared his father's focus on baseball
what is the most interesting aspect of Vince and Mike Piazza relationship?
Vince Piazza saw that Mike Piazza had potential in the sport, and began encouraging his son to build his arm strength at the age of five.
what followed Mike Piazza's graduation?
Mike Piazza went to South Florida and joined the Miami Hurricanes his freshman year; receiving no playing time that season, Piazza transferred to Miami-Dade North.
any other interesting information in this section of Mike Piazza?
Vince Piazza earned a fortune of more than $100 million in used cars and real estate, and attempted several times to purchase an MLB franchise.

Question: why did this happen?
Self-contained rewrite: why did Vince Piazza earn a fortune?