Arena

To receive 536,000,000 gold pieces, go to a city on Hearts Day, on this day, all inns give free rooms. Just drop by an inn, and ask for a free room, the inn keeper, says that the rooms are free for 24 hours. Now look at the character sheet. Your gold pieces have increased, and you can buy all the spells you want. This may be a glitch in the program, but it's to your advantage, so who cares.