A detailed quote including an end date (prior to which the cost will need to be calculated again). This will include things like hosting fees, domain name registration and outsourcing for different section of the website that cannot be developed by you. Also make sure that you consider including electricity, travel time, consumable and telephone sot in the proposal as well. A good and impressive proposal may take few days but you will be compensated for it. In your anxiousness to get the contract you may lose business if you quote very close to the bone. Keep in mind the factors that very rarely go completely in favor of the plan in web designs and delays can be anticipated. Time is precious. The current rate of web development services must be kept in mind and as per the complexity of the task and efficiency of the designer the services should be charged.