I've got deja vu, didn't you want to do it by bike last year if I remember correctly. I don't know much about buses never use them, Ramsgate station is not all that far from Pegwell 3 miles if that, so getting a cab shouldn't be that expensive, It's what I would do. You want to be careful about timing because Pegwell isn't too good in the morning, the sun comes up over the bay and it is very tidal, time of year isn't too great either.
Come down in the autumn and perhaps we could meet up and I could give you a lift.
Mick