Please help me come up with a negotiation plan from the role(the seller)

you need to address your preparation from your - the seller side -

( when completing your preparation you may include, from your perspective, what the buyer may be doing/thinking and how that will impact your preparation.)

TAN RESOURCE NEGOTIATION SIMULATION Sellers Instructions In this mock negotiation, you will be the seller of an online database of tax research materials. Study the facts carefully and then attempt to negotiate a deal with the opposition. Do not show this fact sheet to the opposition and do not discuss the problem with other members of the class until after you have completed your respective negotiations. You may use any fact or argument that you deem relevant to support your position in the negotiation. You are permitted to negotiate this problem for a maximum of 20 minutes. If you have not reached an agreement within 20 minutes, you must break off negotiations After you have "settled" the transaction, enter the terms of your agreement in your ExpertNegotiator Negotiation Plan Your result for this negotiation will be compared with other sellers. You will be compared solely on the price you negotiate. However, you must negotiate both a price for the database and payment terms