Less if anything.

You buy something from China for $100. Add packing, staff costs and delivery and you sell it retail for say $200. A nice healthy profit margin.

Now you add the 145%, so it costs $245 from China. None of the rest of it will cost you more. Still an extra $100, for $345 total.

The retail customer pays an extra (345/200=) 72.5% instead.

It’s a lot, but not 145%.

So if your retail price goes up by 145% or more, they either weren’t making a lot of profit before, or they’re greedy bastards.