That's why it's so important to read the grant guidelines from cover to cover, and then discuss your project with the funding officers of each agency. They will most likely help you to shape your program so it fits within their priorities. It's as simple as that. Some agencies do not even copy the additional pages that applicants submit when sending copies to grant reviewers. If you are unsure about the price of an item, call a store and get a quote.
Panelists often scrutinize budgets, and look for overbloated expenses as the first area to cut.
Review boards are extremely appreciative of realistic budgets, and reward those who are realistic in their expenses. Believe me, this HAS happened, and you must be aware that once your grant is sent to a funding agency, the information is now public. This will totally destroy your credibility with any agency if you do not present a truthful budget, and will seriously jeapordize future grant applications to that agency. Many granting agencies appreciate a little ingenuity on the part of applicants. For example, if you are able to secure an in-kind donation of goods from a local business, reviewers will be very appreciative of your efforts.