In a Youtube video by ADVChina, the speaker is recommending using a VPN in China for various reasons, and to sign up using his referral code.
He says there are various practical uses including "You could also go and get cheaper plane tickets by hopping around different countries." and shows a screenshot of a flight website called KAYAK, with the VPN software changing his country to Italy.
Is it possible to get cheaper plane tickets by using a VPN in this way? I've never heard of KAYAK, but if I use something like Skyscanner, is it common for tickets to be priced differently depending on which country the user's IP is from?
Is it because of different taxes in different countries? So could it be illegal to get discounts like this? Or is there some pricing strategy from airlines to charge different amounts depending on the country of purchase?