I've been using scav runs on Interchange to explore and note what low-traffic areas have surprising goodies. There is good loot to be found in even the most remote places!
There is an unlocked medical store on the second floor, opposite side of the Mall from Ultra Medical. Go up the Trend escalators and take a sharp left. The loot is worse than Ultra but I still find stims and Ophthalmoscopes there sometimes! Never seen it looted.
There's a furniture store across from the med shop that has weapon crates and valuable spawns. Several under construction stores with utility items. The restaurant tables spawn alyonka's like crazy (I've found 3 in a single raid) and food/utility items in the back. Most restaurant cash registers are unlocked and unlooted. Clothing stores spawn hats and fabrics pretty consistently.
There are definitely better loots spots, but if you are struggling for money or just want to expand your map knowledge, I implore you to check out the random stores! Never know what you will find. I even found a friggin' movie theatre playing live action footage from the Raid series in the back of a bookstore.