I did make about $5,000,000 in my tanking season. I can't rememer the exact breakdown but it was something like:
1) $1,000,000 promotion money.
2) $250,000 a week profit for the first 12 weeks ($3,000,000)
3) Selling players in the first week of the season while prices were high and buying the equilivant replacements after the cutoff during the playoffs as well as getting a couple of mid season bargains ($500,000).
4) Cup money, not having to pay doctors or public relations guys, small profit in the last two weeks and selling the top draft pick which could have been better ($500,000).
Add to that the luxury of worry free training for a whole season.