No sealing here either for standard brick weave drive/patios, with respect to smart seal et al - they are cr@p - esp for drives
if you dig down the customer only wants a sealing service because they think the drive will never need cleaning again
if you seal and you've now done a couple for friends then you will have an idea of time
so I would charge for materials +50% of cost - time to and from job - nominal £30 for rollers/equipment use etc.. hourly rate
I do specialist sealing for sandstone and other natural stone patio's to protect them for the old BBQ
Darran