The EU PlayStation Store has tons of indie titles for PS4 on sale as part of its Totally Digital sale.
Hellblade, Stardew Valley, The Witness, Rocket League, and many others are on sale through the EU PlayStation Store.
Looking over the sale page, there are 345 entries which span full games to add-on content.
Highlights from the sale include the aforementioned along with: Inside, Pyre, Nex Machina, The Vanishing of Ethan Carter, Salt and Sanctuary, Brothers: A Tale of Two Sons, Day of the Tentacle Remastered, What Remains of Edith Finch, and Bastion.
Unravel is on sale for less than £9, and Terraria is £3.99. Those are just two examples of titles on sale for under £9 and under £4.
PlayStation Plus members can also save up to 25% off on select pre-orders, including Tacoma, Gorogoa, NBA Playground 2, and others.
Head over to the EU PS Store to look over the full list.