The likelihood of someone signing the first draft of a sales contract is slim.
If you are on the receiving end, it's crucial to look over every detail of that contract and get back to the offeror with any changes you think need to be made to reflect your original agreement. If you are on the offering end, you should expect the same behavior from the recipient.
In the context of sales, this back and forth discussion is referred to as a negotiation, and it's a key step in the contract management process. These bargaining conversations involve both parties getting as close to what they want as possible while also appeasing the others involved.
Business negotiations can instill stress in even the most experienced sales professionals. Depending on the experience, stubbornness, and sales savvy of the other party, it can be an extremely difficult sales tactic to master.