In principle there is no fee/cost. We do what we do out of passion and intrigue. All we ask for is if the cost of petrol is covered (Can vary based on location). This enables us to carry out the investigation without any negative financial impact.
As an organisation who are self funded, we work on donations. So, if you were happy and satisfied with the service you received. Than of-course we would welcome any contribution towards our research. But, this is optional and at the landlord/persons discretion.