Good advice above. Something I remember my instructor saying (more than once) during my IR was "we'll just do that route (and approaches) again tomorrow". He is just hoping to see if I can get it all right for once, and I'm thinking to myself "thats another £700 he's talking about".
In other words, you must have enough money to be able to cope with these extra hours, or you will be worrying too much about the money ( like I was) and not enough about your flying. This in turn leads to more hours, and more phone calls to increase your credit-card limits.