I'm pretty sure he drank the cheapest stuff when he was a struggling writer, but when he had some money in his pocket, did he splurge on the good stuff? Any anecdotes would be greatly appreciated. Thank you.
There's a bit in Factotum where he's going through a good spell on the horses and he starts drinking good whisky. I think he was only in his twenties at that point though and there's a lot of hard liquor being drunk, mostly cheap stuff but not always. The book is full of great anecdotes.
As he got older I think he favored beer and red wine. He liked to write a bit drunk and said that with whisky within 90 minutes he would be too drunk to write well. Wine and beer were his favorite to write with, red wine in particular. There's an interview where he says this somewhere on YouTube and he's drinking red wine throughout if I remember right.