Steamworld Dig 2 appeared on eBay for £15. The guy had about 10 available and had other games listed for the same price. All new and sealed with free P+P. I bought SD2 and most of the other games quickly sold out except for Ass Creed Origins and FIFA. A few hours later single copies of each game appeared for £4.99 so I bought the last one of as many as I could. Checked again earlier today and more had appeared for £4.99 and quickly sold out.
The user has 1100+ sales, 97% positive, been a user since 2015 and regularly sells AV cables and other cheap items. I assume they've either fell off the back of a lorry or they've got lucky with recent game shops/divisions closing or slimming down (ToysRUs, Grainger, Tesco Direct). I can't understand why anyone would let them go for so cheap.
Don't Play Stationary 4 ever. Switch!