the problem that they're causing is not financial. currency is a social construct; this is not a real concern.
the problem they're causing is in the availability of low rent housing.
this guy is just assuming that the housing to absorb them already exists. this is the fundamental error everybody is making; the fact is that this housing does not exist.
and, so, if you want to cost this properly - if that means something to you - you have to include the cost of building new housing at the appropriate income levels.
so, how much does it cost to build thousands of new housing complexes that families on welfare can afford to live in? tens or hundreds of millions?
you can't increase the population by 200,000 people in a few months and expect not to have to build houses for them. that's crazy.
https://www.cbc.ca/news/canada/armstrong-refugee-costs-1.4762930