In DnD 5e’s lower magic approach, how would the Red Wizards of Thay’s magic item business work out?

DnD 5e makes magic items much less common than previous editions. Also, the Forgotten Realms are the assumed background even in the Core Rules.

One of the most interesting groups in Faerun are the Red Wizards of Thay, trying to gain money and influence by building enclaves all across Faerun where they produce and sell magic items.

Now these two concepts do not go together well. Still, as Faerun is the assumed background, magic items there are also supposed to be rare (i.e. Faerun is not a particularly high-magic setting).

I want to include the Red Wizards in my upcoming DnD 5e campaign, but I’m unsure how their strategies might work out. Would they rather demand favors and support than money for their magic items? Or are they an exception to the rule that magic items are not for sale, where the flip side of the coin is that every magic item bought supports a magocracy with overt slavery and oppression?