His initial investment back in 2004 was only like $40 million. The team was worth $400 million at the time, but that included taking on $200 million in debt, so it was really only worth like $200 million. So Sarver's initial ownership % was only like 20%. I think later he purchased Bryan Colangelo's stake when he became the GM of the raptors, but not sure how much those shares went for.
The team is now worth like $1.8 billion. So with a 35% share, his portion is worth like $630 million. Not a bad investment from his original $40 million plus the extra he paid for Colangelo's shares.