richy
if you set up google adwords, your report will tell you what level it suggests, and also if any particular word or phrase is under the amount that it needs to be listed.
it will also highlight if any word or phrase isa low search value, and therefore you can then delete it from your campaign,
ive had campaigns set up at £3.00 per day, but you can also set your account trigger the ads at sertain times of the day, and in certain geographical territory.
but its also about monitoring it productively and changing budgets as and when required.
regards
martin