Magic item availability in cities

[Rolero]

Hello fellow adventurers, on my last season last night my players ended up with lots of money. Not only were they able to find buyers for a lot of expensive items, but also resolved a quest that lead them to a decent hoard.
Of course, with so much loot, they turned to me and ask: can I buy magic items in town? During their selling spree they have already find a shop that may have what they want (Ferdinand's Wondrous Boutique) and while I said that rare items or higher should not be available, there is still a lot of powerful items on the uncommon category they could easily buy with their deep pockets.

So, how many of this should be available and for how much? I made a point to tell them that in my campaign higher magics and wondrous trinkets are quite rare. Still, some of the things on their wishlist include +1 weapons and armor (which I'll allow) but also Winged boots, Cloak of protection, Cloak of Manta ray, Pearls of power, and others. While I don't see this items as overpowered, I want to be consistent with my world and find a way to restrict the avaliability (the may appear weeks later, but not all at once).

How do you manage did kind of situations on your games?

[Unoriginal]

The Xanathar's has rules to buy magic items.

If you have a shop where one can buy uncommon, non-consumable magic items, you're probably looking in the 500-1500 gp per item range, so it's up to you to decide how many items it makes sense for this shop to have in stock.

Unless there is a specific reasons for this shop to have one item (ex: the owner has the formula for a Robe of Eyes), I'd just roll the items on a table and let random chance decide what they came across.

Don't tailor it to fit the PCs' wishlist/shopping list. If they're really interested in one item, you can give them a rumor about X bad guy who's doing Y and who might have the magic item they want, or a rumor about X place/dead person who could have this item.

Ex: "Winged Boots? Last time I saw a pair it was the ones of Jabb, the explorer. He left one day for a cave in the mountain and never came back."

[Lunali]

You could also have a shop that has connections rather than actually having magic items. Then they could either find out where they need to go to get a specific item, with a small discount for a referral, or have it sent to the shop for an increased price (a good chunk of which should be in advance) and a bit of waiting around.