Not very hard for me, but was hard for a few of my friends. One had a problem with playing casino (self-explanatory). The other needed 'to make it work', as it was a part of his monthly income. If you NEED that money, it's likely you will break the bankroll management and burn (or win big, who knows). If you're building a solid house, and have your finances in check without poke (so that any winnings are a bonus not a necessity), you will probably find it easy.
That said, I break the rules from time to time when I see significant extra value to be gained potentially, but in a way that wouldn't set me back too much, may be up to 10-15% for 1 BI.