In Blighty, most people do not buy red potatoes coz they are dear.

Here in Inner Mongolia they are relatively cheap if you buy a big sack of them from a wholesaler. There is a huge difference in taste between red tatties and white tatties. During certain times of the year, when red tatties are unavailable, I buy new white potatoes, also in bulk. Inferior to reds, but acceptable short term as a stopgap.

Brown mushrooms are far superior to button whites, or any other whites. Brown mushrooms are very tasty with mutton/lamb hotpot. Cost here around 7 rmb/500g fresh at present. Sometimes available at 5 Yuan/jin. If so, go for it! Cut the stalks off, they are a tad tough.

You can also buy dried brown mushrooms. The stalks have been removed.