In an ideal world every project would have an unlimited budget and nothing would be impossible.
In our experience a tight budget actually improves performance because it encourages innovation.
Consider the following to help set your project budget.
1 Internal costs
How you account for your own time or those of internal resources if they are to be dedicated to the project?
2 External costs
Consultants, research, designers, print / construction costs, Advertising and Public relations
3 Opportunity costs
Consider one off costs particularly with a new brand where there is no historical finance model to follow.
Always make an allowance for the unexpected. Depending on the size of the project we would advise between 10-15%
If you are working on a fixed fee basis you may be asked to pay the fee in stages corresponding to a schedule. For smaller projects it is common to pay 50% on commission and the remainder on completion. the project proposal should be clear about how outside costs and expenses are to be billed and if there is any mark-up for administration. (10-20% is not uncommon)
If you undertake to pay promptly you may be able to negotiate a discount.
Half the money I spend on advertising is wasted;
the trouble is I don't know which half.
US store owner