Xanathar's Guide - Downtime, buying magic items

[nickl_2000]

Looking at the downtime rules in X's for buying magic items and I'm slightly confused.

A player is searching for a specific uncommon magical item. They need to roll a DC15 persuasion check to get a specific item. Do they also get rolls from the treasure tables? So, a roll of 21 persuation gives the specific item and Roll 1d4 times on Magic Item Table E? Or just the specific item they want?

[Reynaerde]

The way we've been handling it is that you roll on the tables like you normally would. However, if the DM said a certain item would be allowed and you manage to roll high enough for its rarity, you find that one and roll for one less random item than you normally would.

Hope that helps?