Indies are usually shorter, so I usually make exceptions for them despite having tons of unplayed games, especially during holidays when I have more time to play.
I’m a lot more conservative with buying AAAs though because they’re usually longer and have steeper discounts after a few years. So if I’m not super excited to play them right now, I can usually buy them next year at like half the price.
So for me, I’ll pick up indies at 20-50% off, and AAAs at 60-80% off, unless I’m really interested in the game (i.e. I’d start it right away).