Yes, they were well paid
Then there were the books, personal appearances and so forth.
Thing is the two women really didn't get on. Off camera things could and often did get quite interesting.
http://www.dailymail.co.uk/tvshowbi...nds-fascinating-insight-loved-double-act.html
As for their cooking/choice of recipes, the TWL weren't chefs but cooks really. The foods made on the show (and often found in their books) are what formed a bulk of what could be called British cooking for ages. All that fat, suet, drippings, meat, cream, puddings, rich foods, baked goods, dairy and so forth formed the basis of how anyone who could afford it ate.
Well past WWI or even WWII certain class of persons had several courses for breakfast, another round at luncheon and far more at dinner. Oh and don't forget tea time either. Of course back in the day people got more exercise than they do now. Even the wealthy who didn't work per se rode (horses), played sports, took walks, etc....
Also many of the TWL recipes took advantage of the AGA or similar range they were bound to find at these locations. AGAs and other such ranges were and perhaps still are popular in the cold damp climate of Great Britain. However preparing meals on such a range does tend to limit one's creativity in the kitchen. Since you cannot control heat directly but must resort to moving things around dishes that require fine adjustments in heat are usually out. That leaves boiling, frying, roasting, and baking pretty much.
The TWL took a lot of heat for their excessive (to some) use of lard, butter, bacon, suet and other fats. However we must remember that is what one cooked with before hydrogenated fat (Crisco) and margarine came along. Have had pies where the crust was made from either suet or lard and they beat anything made from Crisco by a mile.