Customer service of cheap prices, which sells more in your opinion?

Cheap prices would sell in the short run. But in the consumer durable   industry (computers, printers, mobile phones, radio and tv) cheap prices alone would not sell. You need good customer service for products in warranty and chat support and other support groups for products even out of warranty. Other wise the customers would vent their anger in the social media negating the cheap prices.

I think it depends on for how long the customer wants to use the item or service.  For short use items maybe you can get away with being cheap, and providing less customer service.  But for longer term services and durable items, as my grandfather always said, "I'm poor, so I can't afford to buy cheap."  He couldn't afford to buy the same item over and over, he wasn't rich like that.

I would restrain from using the word cheap. However, it is not necessary that services at low price would sell more.