Where are you planning on parking when you get there though?
I'd rather pay quadruple for a ticket to London, than drive into London and then try to park a car. I can't imagine driving into a city - seems insane.
I am originally from the outskirts of Glasgow and now live on the outskirts of London. For my partner and I to get to my parents house by train takes about the same time (assuming all 4 changes go according to plan), costs 6x as much and is far less flexible than driving. We tend to stop at a cheap hotel midway so we can set off after I finish work.
But often the reverse is true - if your meeting isn't in the middle of London, it's much easier to drive directly to the place than get there by changing trains. This applies even more if your destination is a smaller place.