If I ______ (be) in your position, I would try to negotiate a better deal.

The correct form of the verb to fill in the blank is "were." Therefore, the complete sentence is: "If I were in your position, I would try to negotiate a better deal."

This sentence is an example of the second conditional, which is used to talk about hypothetical situations that are not true or are unlikely to happen. In English, when we express a hypothetical situation regarding something that is contrary to fact, we use "if" followed by the past subjunctive form of the verb "to be," which is "were" for all subjects (I, you, he, she, it, we, they).

The structure of the second conditional is as follows:

- If + subject + past simple verb (in this case, "were") + , subject + would + base form of the verb (in this case, "try").

In summary, "If I were in your position" suggests that the speaker is not in the listener's position, but is imagining what they would do if they were. Using "were" instead of "was" emphasizes the hypothetical nature of the statement.