DDR5 is widely available now and prices have dropped a lot. So is it actually worth switching from DDR4?
Performance
DDR5 wins on bandwidth. Base speeds start at 4800 MT/s, with high-end kits pushing 8000 MT/s and beyond. If you're doing video editing, machine learning work or gaming at high refresh rates, you'll likely feel the difference. For everyday use? Probably not.
Price
DDR4 is still the better deal for budget builds. Use RAM-Mageddon's price per GB sorting to see which option actually gets you more memory for your money.
Platform compatibility
DDR5 needs a compatible board and CPU. Intel 12th gen and newer works, AMD Ryzen 7000 too. On an older platform, DDR4 (or lower) is your only option.
Bottom line: Building new on a modern platform with some budget flexibility? Go DDR5. Upgrading an existing rig or building on a budget? DDR4 still does the job very well.