I think the idea that the Koreans have is that business is business. You buy stuff for 30ยข and sell it for $1.29 and you make money. The privately owned dollar stores (as opposed to the national brand stores like Dollar Tree) used to have some bargains, but most of them here sell crap at high prices. There is one in North Miami Beach that I visit every week, though that always has some bargains. Breakfast cereal for $1.59 that normally sells for $3.00. Lately, they have been selling a lot of wine at 4 bottles for $10, and some of it is fairly good.
I am no wine connoisseur, but my experience is that restaurant wine is uniformly both bad (as in it tastes like vinegar) and hideously overpriced. The only surefire never bad wine I have found is Argentine Malbec. Jewish sweet wine (Manischewicz, Mogan David, etc.) is also reliably sweet and makes great sangria, it you like sangria. It is better to buy sweet wine and not have to sweeten it than to buy dry wine and throw in a lot of sugar. At least that is the way I like it.