Selling land - minimum fee

We have a garden which is separate from the house (this is a very old property, with an old layout). We are selling up, and think it would be best to sell the land/garden first. Over the years a number of people with adjoining land have expressed interest in this little parcel of land and said that they would like to buy it. We always refused, as, as long as we lived in the house, we wanted the garden to have as a garden. But now that we have decided to sell up, we want to put it on the market.

We have had a chat with a local estate agent, a firm that has been recommended, and, because a parcel of land does not command the price that a house would, have been proposed a minimum fee of £1,200 + VAT.

Trouble is, we are not entirely sure what the land will go for, so don't want to overspend on the fee, ie: the fee might turn out to be rather a large percentage of what we would get for the land.

However, going through an estate agent would be the best way of selling, as it would make the neighbourhood aware that the property is on the market.

Question: does £1,200 seem like a reasonable minimum fee to sell a garden? We expect that a number of people will be in competition to buy it, and I expect the land to sell for something between 20k and 40k. It is, however, hard to predict what it will go for.

The land is a potential building plot. It is landlocked for vehicular access, (there is pedestrian access via a right of way), but at least two potential buyers would have vehicular access via their own properties. A third potential buyer is selling a nearby building plot with planning permission, and this is only separated from our plot by a section of a long garden.

Purchase of the plot could boost the value of adjacent properties. It would also, in effect, end the right of way across two properties, including a potential purchaser's property.