Electronics aren’t necessarily more expensive, Europe just has VAT included in the price. Amazon.be, .de, and .se all deliver to Denmark, often with free shipping (although Amazon.de recently increased the free shipping from 29€ to 59€)
All that said I'm not sure about this guy's tax rate, just there are probably wrinkles here that will make things come out weird if not taken into account.
on edit: although his phrasing makes it sound like it is applying to all Danes, which anyway would be weird, why would you care what Danes pay if your concern is figuring out the cost/benefits of you (or someone like you) moving somewhere.
The only reason this is even a thing in tech, is because of the massive taxation of salaries above ~$100k. If i recall then whatever personal income in the upper bracket is effectively taxed at ~60%, which sucks. It makes it extremely expensive for the employer to give meaningful raises to top performers, and creates an artificial ceiling on salaries that is really hard to break through, unless you go freelance, but that comes with a lot of uncertainty and extra work. I prefer full control over my income and accept the uncertainty in exchange for that.