Sometimes people are interested in saving money or they are on a very tight budget. While there are things that can be done to reduce excessive costs, there is usually a minimum price point, below which, the project is just not feasible.
People often think that getting the flowers and having friends help with the arrangements can save money. Sometimes it can but it adds a whole new level of stress to the process. There is buying the flowers, cutting and storing them in a cool place, preparing the arrangements, transportation and setup. Then there is the cleanup! You may save some money but it will still cost in money, time and stress in the end.
A word of caution: Wholesale florists and professionals frown on this approach. Low bids and underestimated quotes that never deliver create a perception of savings that end up undercutting professional proposals. In the end, most would be better off budgeting in the flowers as a package.