Tariffs, on anything, are not based on retail prices. They are based on the price the US company pays the Chinese company for the product.
Do you pay retail for your model trains? No one knows what price a product will actually sell for.
There is already a lengthy discussion about the tariffs and the possible cost effects elsewhere on this forum. Can’t say I really know how to link you to it. Maybe this works:
https://forum.trains.com/t/current-tariffs-and-your-model-railroad/411659/72
But in simple terms, it will be up to the manufacturers and dealers to determine how much they will need to raise selling prices to cover this added expense.
Since you and I can only guess at what their “actual” cost is, we can only guess what the increases might be.
I suspect that all the tariffs are more complex than what we hear in the news. But the effect on selling prices could be as low as 7% or as high as 35%
If the manufacturers and dealers can afford to, they would be smart to just “pass thru” the tariff with no markup. That would keep price increases below 10%.
When you buy retail directly from Canada, that is a different set of rules that I do not know all the details of. But if that order is with Rapido, you might want to find a press release from them that explains their plans to keep US prices as low as possible.
Sheldon