Those prices are tempting, but the total cost of travel needs to be taken into account - not only the cost of getting to/from the airport, but the individual's valuation of the time expended (especially given the OP's statement about it being frustrating to spend a day doing this).

I don't know whether the OP is in a situation like mine, but I can reliably leave the office 90 minutes before STD of a flight from LCY and still have plenty of margin for unexpected Tube/DLR delays, and reliably put my key into my front door lock less than 35 minutes after the aircraft's parking brake is applied at LCY.

So there are things that the OP needs to take into account, about which we don't know enough to be definite about which of the options is best/better for him. Hopefully the OP will be able to weigh up all the considerations and make a good decision for himself.