
Most sellers and agents are happiest with a sole agency arrangement. The seller has only one point of contact and the agent's chance of earning a fee is greater.
Typically the fee that you will pay for this service will be around 2% of the selling price (to which you need to add VAT) and will be less than for a multiple agency.
Before agreeing to such an arrangement you must be certain that you have found the right agent as they are likely to contract with you for a minimum period. Instructing other agents during this time could lead to you having to pay two fees!
You may feel that competition between agents is what is needed to get the best price possible. However will they make the same effort or use the same amount of resource, as the odds on them selling will be considerably reduced, and so might their interest.
You will pay a higher fee, around 3% of the selling price (to which you need to add VAT), so you will need to be convinced that the additional investment in fees will be repaid by one of them eventually achieving a higher price.