In Canada ... prices are shown without the 13% HST ... because virtually everything you buy has 13% added to it ... the Harmonized Sales Tax is just a given.
HST ... "Harmonized" sales tax... That's a laughable term.
Back when it was first introduced about a decade and a half ago, it made real sense -- every province which signed on to the program would have the exact same sales tax ... making it easier for businesses to coordinate their pricing across the country, making it easier for consumers to predict the price of any inter-provincial mail-order sales, etc.
But then, very few provinces signed on, which only served to complicate inter-provincial mail orders -- GST+PST when selling in-province, GST-only when selling out-of-province to most customers, HST when selling to a select few out-of-province customers...
Then some provinces started exempting certain classes of products from the provincial portion of the tax...
All of this effectively killed the "Harmonization" of the sales tax.
Later, when ON and BC joined the HST bandwagon, NS took the opportunity to use a loophole in its agreement with Ottawa, to raise the provincial component of its HST, so the "Harmonized" tax in NS doesn't even use the same percentage as the "Harmonized" tax in all the other provinces which use it.
It's a mess.
By the way, back in the day, there was no federal value-added tax in Canada. Most provinces had a value-added tax, but the federal government took its cut by taxing companies directly for the value of all their output of manufactured goods. The companies complained that this was needlessly hurting their international competitiveness by inflating the prices of any products they exported. So the federal government reacted by scrapping the manufacturers' tax, and introducing a federal VAT, which they called the GST.
Originally the proposed regulation would have been that the GST would be included in all advertised consumer prices -- which was expected to result in roughly maintaining the status quo, because manufacturers used to have to set their recommended retail prices based upon their own need to recover the cost of the manufacurers' tax. (Except for the "services" industry, which had never been subject to a federal sales tax before the GST.)
But that was scrapped in favour of making it up to the individual retailer to decide whether to advertise their prices pre- or post-GST. The vast majority decided to advertise the pre-GST price, and it has remained that way.