I'm considering building a desktop for roughly €300–500, mainly for lightweight indie games and League of Legends. I already have a Lenovo IdeaPad Flex 5 with a Ryzen 5 5500U and 8 GB of RAM, but games other than League run poorly on it. I use an Xbox Series X for demanding games and plan to keep doing that, so this PC doesn't need to handle modern AAA titles. I'm mostly looking for something practical that can run indie games comfortably and offer a better PC gaming experience. I'm not very knowledgeable about hardware, and I've heard that current RAM prices and availability may make a budget build difficult. I'm located in Paris, so advice based on the French used and new hardware market would be especially helpful.
3 Answers
Your best value will probably come from buying used parts or a complete second-hand system. For around €500, try to find something with at least a 6-core processor comparable to an Intel 8th-generation i5 or Ryzen 5 2600, 16 GB of RAM, and a graphics card around the GTX 1070 or RX 580 8 GB level. That should be more than enough for League and most indie games at 1080p. I’d avoid going much below 16 GB of memory, since 8 GB can become restrictive quickly.
I’d strongly recommend buying the power supply new rather than used, especially if you’re not comfortable judging hardware condition. A reputable 80+ Bronze unit around 500–650 W is plenty for an RX 580 or GTX 1070-class card. The case can be inexpensive or second-hand as long as it has decent airflow and supports the motherboard size. You can also skip a hard drive at first and use one SSD for the system and games; add bulk storage later if needed.
It’s possible, but a €300–500 prebuilt is unlikely to be very impressive. A used build could work well if you shop carefully. One sensible parts combination would be a Ryzen 5 2600 with its stock cooler, a B450 motherboard, 2×8 GB of DDR4, and an RX 580 8 GB or similar graphics card. Add a reasonably sized SSD for the operating system and games. This setup is older, but it should handle League and basic indie gaming comfortably at 1080p.
The Ryzen 5 2600 supports fast DDR4 less reliably than newer processors, so don’t assume every 3200 MT/s memory kit will run at its advertised speed. It can still be useful if you upgrade the CPU later, but stability matters more than the rated speed on this platform.

Thanks! I’m in Paris, so I’ll check the local used market. What price range would you consider realistic for a decent budget PC?