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They can state a lot of things in their ToS, but they will still have to follow the law.
Thankfully though, the law does realise that mistakes happen. When a price-change/discount is believable (and i gues "believable" is something you can fight about in court) they will have to deliver the goods. However, with an obvious mistake like this, razer will of course not have to ship anything for that price.
This is how it works in the Netherlands at least, if i remember it correctly from the couple law course i've followed.