As a tyrant you should have no problem upping the rent on houses and shops etc to actually make more money as you wont mind the negatives of having the people dislike you more. If you playing as an evil character you can also steal items from shops again without worrying too much about it affecting your moral. also, not going to spoil the game, but some harder decision making later on will earn you more gold but will be considered "evil".
I'd say it'd prob. be somewhat easier to earn gold as an evil character than playing as a good one I may be wrong here though.
