Would you go ferry via Ramsgate or chunnel via London? Cost is a factor (more or less), time is not (more or less).

Well, before asking the question, I'd check whether the Ramsgate-Ostend ferry accepts foot passengers: increasingly, most cross-Channel ferry companies don't.

The quickest way (yes I know what you said...) is train to Ashford, train to Brussels, train to Bruges. All more or less cross-platform connections, with none of the luggage shlepping that's an essential part of the horrors of being a foot passenger on the few ferries that offer the service. You CAN avoid the cross-London tube connection by getting the fast - but premium-priced - train to St Pancras, but it still takes three times as long as the train to Ashford.

Which is cheaper? No idea. Only you know when you're going - so only you can find out the price.

You could also take the Eurolines bus to Bruges from London. The current listed price is 28 pounds. Here is the schedule/fare list
http://www.eurolines.co.uk/eurolines_ims/pdf/ELW03.pdf

Train from Canterbury to Ashford (20 minutes) the Eurostar to Brussels - buy eurostar in advance and that's most likely to be both the quickest and the cheapest option.

Given the Eurolines coach goes via Dover, it would be simpler to take the train to Dover from Canterbury and pick up the coach there

hope you have no luggage, the dover station is at least 2 miles from the port....

There is a shuttle bus from Dover Priory to Eastern docks though.

Foot passengers can't use the Ramsgate Ostend route.

Also the Eurostar to Brussels from Ashford leaves at 06.57 Mon-Fri, at 08.28 on Sat, and at 18.55 on Sundays. Only one departure per day.
The train to Dover, shuttle to the docks and Eurolines to Brugge is maybe easier, and almost certainly cheaper.

I believe the OP wants to drive, no?

Why not Norfolk Lines Dover - Dunkirk usually cheaper and its nearer?

"I believe the OP wants to drive, no?"

If so "Chunnel via London" would be a pretty weird way of doing it.

Isn't Folkestone considered a London suburb?

haha - London suburb - hope you are joking