I'm completely new to building PCs and have a total budget of about $300. I'm considering a Ryzen 5 3600, a B450 motherboard, 16GB of DDR4-3200 memory, a basic tower cooler, a 512GB NVMe SSD, and a GTX 1660 Super, along with a 500W power supply and a budget micro-ATX case. The exact brands are flexible. Prices are unusually high where I live, so I'd appreciate advice on what to change, which parts are safe to buy used, and how to find the best online deals.
3 Answers
The overall parts list is reasonable for an entry-level system, but fitting all of it into $300 will probably require buying several components used. Prioritize the graphics card and avoid overspending on extras like an aftermarket cooler if the CPU includes one or you can find a cheap alternative. Check local used listings for combinations such as a Ryzen 5 3600, 16GB of RAM, and a compatible motherboard. Prices vary a lot by region, so your location would make deal recommendations more accurate.
With only $300 for the entire computer, newer graphics cards aren’t realistic recommendations because one card could cost the whole budget. Look for a used GTX 1660 Super, RX 5600 XT, RX 5700, or a similar older card, and compare complete used PCs as well as individual parts. A ready-made used system can sometimes be cheaper than assembling one from scratch, especially if it already includes memory and storage.
I’d be cautious with the power supplies listed. A decent 550W or 650W unit from a reputable model line would give you more safety and room for a future graphics-card upgrade, even if you have to choose a simpler case or smaller SSD to make room in the budget. Don’t choose a higher wattage unit solely based on the number on the box—quality matters more.

That makes sense. I’ll compare complete used systems too instead of assuming individual parts will be cheaper.