For PS Plus members only, PlayStation Store offers downloads of Call of Duty: Modern Warfare Remastered for PlayStation 4 for free. That's the lowest price we could find by $20. Also available for PS Plus members are downloads of The Witness for PlayStation 4 for free. That's $40 off and the lowest price we could find.
Frugal isn't smart if you put off replacing these things. Waiting too long can cost money or even endanger your health.