". . . we have been contacted by a person who in interested in the house but has not yet seen it . . ."
How'd this person find out about your property . . . . it's not even listed yet ?
If this person is so interested, why not sell it directly yourself, and save the whole Commission ?
If you've "been in contact with a couple realtors"
; but haven't listed the property yet, then tell them that you're listing it with the one who'll cut the Commission by 1 or 2% IF you find a bonafide Qualified, Ready, and Willing Buyer
(completely independent of the Broker's efforts).
The woodwork must be loaded with curious and interested people who are always waiting for soon-to-be-listed property to come available . . . . hopefully yours is real !