Cheapest option for Toronto /NYC with 2 teens

[medianewbie]

I want to take DS (18) & DD (16) to Toronto for 5-7 days. I'd really like 2 of those days to be in NYC if possible.
On a shoestring. Happy to stay Uni accommodation/ YHA accommodation (does it exist in USA / Canada ?)
Where is best to find cheap flights ?
Do I need to book visas separately?

We can go 1-10 Aug or 1st week Jan.

Harmonised Sales Tax in Ontario is 13%. The price you see isn’t the price you pay, as the tax is added on at checkout, not incorporated in the price like VAT is in the U.K.

Goodness OP if you manage to do three adults to Toronto including flights, accom, all good and spending money for £3k - you have got a truly incredible deal.

Although the fact you think your experience of scottish winters will prepare you for Canadian - would indicate you are a very optimistic person born about the cost of holidays and Canadian weather!

I was on this thread under a different name

op - did you book?

And if you did £