Not really. The TA recruit people who have already been trained in useful skills in civilian life where possible, so the army doesn't need to pay for their training from scratch. Obviously, there is nobody in civilian life who already knows how to operate artillery or what have you, but a civilian nurse largely is similar to a combat nurse, so the cost of the extra training is massively reduced.
That's actually the point of the TA. Everyone has the image that TA are all 'weekend infantry' but in the main, they're not. The regular army do all the front line stuff and the TA are largely used to fill in all the 'behind the line' specialist posts that are needed as well but you don't need to be a combat soldier to do.
