Very good answer by MareeClara. I think the one thing she missed is the budget.
At this time, a round trip plane ticket will be around $Can 1000 from Toronto, more from the west coast.
For hostel and cook your own dinner travel in Europe you need to budget about $100 per day each, so for a month that is about $3000 each.
On top of that will come some costs you will pay at home, like your insurance, and maybe your rail pass or bus pass if you use one.
It is very easy to spend more, it is harder to spend less but it is possible.
I think a $5000 tour will cost about the same as traveling without a tour, but on top of the tour comes pocket money, which you will not need when traveling without a tour. And if you are into partying, a tour can cost you half as much again in extras and drinks.
But by the time you will actually travel, likely the prices as well as the exchange rates will have changed.
So keep an eye on cost predictions here, but as a general rule, the price for those tours will be about the same as individual travel, before adding the pocket money.