Prices have generally fallen 30% from their peak so the figure the EA is quoting doesn’t seem out of that ballpark.
The only way of actually ascertaining the value is to look at what similar properties in the same area are fetching (n.b. Fetching, not the asking price which are often, as yours currently appears to be, ridiculous.)
Have a look at the ‘Sell your property in Spain’ forum on here. At the top there is an explanation of how to insert photos. If you can’t manage with that then why not get someone a bit more computer literate to help you.