To be fair, and this is coming from someone who would never vote Tory (probably). To be fair, we already know what the cost of a Tory government is. It's the status quo.
Okay sure, scrapping free School Lunches and replacing them with free School Breakfasts was costed wrongly. Okay sure, maybe things like Brexit is going to feck us. Okay sure, maybe there are a couple of policies that will increase the burden on general taxation.
But by and large we know what the costs are, because we already have them. The Tories could have produced a one page manifesto by just writing "pretty much the same as now" and handing that in to the teacher.
Labour want to nationalise the Royal Mail, Water, Energy and Trains. They want a national investment bank. They want a £10 minimum wage. They want to tax the rich, and tax big companies.
The burden of proof is on Labour. We already know the Conservatives plans work. Or don't work, considering the deficit.