Once you have compared the offers and ranked them according to your criteria, you can start negotiating with the vendors. Negotiation is not just about getting the lowest price, but also about creating a win-win situation for both parties. You can negotiate on various aspects of the offer, such as the scope, the quality, the timeline, the payment, the contract, and the extras. You can also leverage your alternatives, your relationship, and your value proposition to persuade the vendor to give you a better deal. However, you should also be respectful, flexible, and realistic in your negotiation. Don't ask for too much, don't make unreasonable demands, and don't compromise on your core needs.