Actually, Paris to Le Mans is about 210 km, while Calgary to Edmonton is more like 300 km.

A TGV ticket from Paris to Le Mans costs from 28 to 38.5 EUR in 2d class, and from 31 to 75 EUR in first. So, the $100 figure is not necessarily representative in that this would be a full fare fully flexible first class ticket.

OTOH, trains in France are rather cheap. I would guess the railway gets its electricity heavily subsidized. If you look at the price of tickets in germany you'll see prices are often quite a bit higher.

So, in the end I agree with you that high speed trains are not that cheap. The real issue is infrastructure cost. In the end, it takes significant traffic to dilute these costs to reasonable levels. A Calgary-Edmonton line would likely not be commercially viable. Of course there are always governments willing to pour taxpayer money into white elephants.

I recently traveled on high speed trains of all places in China. A first class ticket between Nanjing and Hefei, which is a one hour and five to ten minutes trip costs 80 RMB, i.e. dirt cheap, something like $12-13. But then infrastructure costs are mostly labor. And for better or worse, they poured tons of money in support of their economy.