Is it worth spending $50 to upgrade RAM on an old Haswell system?

Probably not. 8GB is tight for browsing these days, but 16GB won’t turn that Haswell into a photo-editing beast. Lightroom or GIMP will still feel sluggish because the CPU and old DDR3 speed are the real bottlenecks. Put that $50 toward a newer system — even a used one will feel like a bigger upgrade.