Should I buy DDR4 or DDR5 RAM for a new PC build in 2025?

Go with DDR5. A 32GB DDR5 kit costs roughly $90–$110, only $20–$30 more than DDR4. The gap is small enough that you shouldn’t overthink it—DDR5 offers real performance gains in bandwidth-heavy tasks and future-proofs your build. The only exceptions are upgrading an existing DDR4 system or a super-budget build where every dollar counts.