Deciding on a list price is not just a simple math equation. Good agents have to consider several variables to include location, condition, and market value.
Your agent should present a market analysis to you that backs up their suggested sale price with real comparisons. A good market analysis will involve deep research of recently sold properties on the multiple listing service (MLS), any private sales the agent can track down, a knowledge of local appraisals, and public documentation that may affect the property (like surveys, easements, and zoning).
Your agent should also walk you through the strategies of pricing slightly below market analysis value (aiming to stir up a multiple offer situation) or slightly above market analysis (shooting for a higher sale price by targeting those buyers who really want the home and can afford the asking price).
Ultimately, you need to really trust that your agent has the skills to do the best job possible and the dedication to your most favorable outcome as their highest priority.