Research by the party found that local authorities have committed almost £600,000 worth of resources to investigate the feasibility of a basic income scheme for Scotland.
The Scottish Government has pledged £250,000 to help North Ayrshire, Fife Glasgow and Edinburgh councils carry out local pilot work.
Documents released to the Tories under freedom of information legislation show that together the councils propose to support the pilots with an additional £450,530 worth of staffing resources as well as £114,000 in cash.
In addition Fife Council has already undertaken background work on the idea of a basic income with funding of £34,000 awarded for 2017/18.
The documents also refer to an unspecified staffing contribution from NHS Health Scotland.
Tory social security spokeswoman Michelle Ballantyne said: “This initiative is an SNP vanity project which even its own advisers think is a crazy idea.
“It’s completely unaffordable, unsustainable, and will end up harming those it’s supposed to help.
“While I may not have agreed with spending the initial £250,000, I accept that some people felt that it was important to test the theory.
“But that cost to taxpayers has now trebled before it’s even begun, which is a strong indication about just how chaotically expensive this will become.
“And once the NHS elements are factored in, the costs will be well on their way to £1 million.
“The scheme should be dropped now before any more taxpayers’ money is wasted.”