What would it cost to build this PC?

The same parts as the Mantis V2 Gaming Desktop PC - (NVD GeForce RTX 5090, AMD Ryzen 7 7800X3D 8-Core Processor, 64GB DDR5 RAM, 2TB NVMe Gen4 SSD, HDMI, WiFi + BT, KB&M, Windows 11 Pro) - Prebuilt RGB Gamer Computer Tower, bought one by one at Best Buy and Newegg today. Prices as of Oct 1, 2026.

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Best Buy subtotal $165.49

Power supply Not listed on the prebuilt
Lian Li - RS 1000W Modular PSU (USB Fan Hub, 90° Inlet, 80+ Gold, 10Y Warranty - White
The prebuilt doesn't list its power supply: 1000W 80 PLUS Gold (enough for this graphics card)
$165.49
Buy at Best Buy: Lian Li - RS 1000W Modular PSU (USB Fan Hub, 90° Inlet, 80+ Gold, 10Y Warranty - White (opens in a new tab)Swap / Upgrade: Power supply

Newegg subtotal $1,763.86

Memory Closest equivalent
G. SKILL Ripjaws M5 RGB Series 64GB (2 x 32GB) 288-Pin PC RAM DDR5 5200 (PC5 41600) Desktop Memory Model F5-5200J4040A32GX2-RM5RW
The same 64GB DDR5 at 5200 MT/s (2 sticks)
$959.99
No tracked link for this part today
Swap / Upgrade: Memory
Processor Exact match
AMD Ryzen 7 7800X3D - Ryzen 7 7000 Series Zen 4 8-Core 4.2 GHz - Socket AM5 120W - AMD Radeon Graphics Desktop Processor - 100-100000910WOF
The same Ryzen 7 7800X3D
$416.00
No tracked link for this part today
Swap / Upgrade: Processor
Storage Closest equivalent
WD Blue SN5100 2TB NVMe SSD, PCIe Gen 4.0, up to 7,100 MB/s read speeds
The same 2TB NVMe SSD
$279.99
No tracked link for this part today
Swap / Upgrade: Storage

Not found today

Graphics card: No RTX 5090 card at Best Buy or Newegg today Pick one yourself

Do the parts fit together?

No problems found. We only check what the stores' listings say. "Check fit" means they don't tell us, so look before you buy.

Check fit The motherboard's listing doesn't say its size. Make sure the case takes this motherboard.
Check fit We don't have the cooler's height or the case's CPU cooler clearance. Compare them before you buy.
OK The processor and the motherboard are both AM5.
OK The memory and the motherboard are both DDR5.

Windows 11 Home license: $139.00 (Microsoft's price; leave it out if you already have Windows)

Total: $2,068.35 (without the parts not found today)

Shipping and tax are not included.

Save this build

Buy the whole list

Each button opens that part at the store in a new tab: add it to your cart there, then come back for the next. We tick it off as you go. Prices can change at the store; shipping and tax are not included.

0 of 1 parts added: $0.00 of $165.49 in parts

Add these parts to your Best Buy cart

Power supply Lian Li - RS 1000W Modular PSU (USB Fan Hub, 90° Inlet, 80+ Gold, 10Y Warranty - White $165.49Add to cart at Best Buy: Lian Li - RS 1000W Modular PSU (USB Fan Hub, 90° Inlet, 80+ Gold, 10Y Warranty - White (opens in a new tab)

The prebuilt: $5,249.99 at Walmart

We can compare once every part has a price today.

Buy at Walmart

Prebuilt or build it yourself?

What the prebuilt includes: The $5,250 prebuilt comes assembled and tested, with Windows installed, one warranty for the whole PC and one place to call for support. Parts come with a warranty each, and you install Windows yourself.

Where it may cut corners:

It doesn't list its power supply; an unbranded one is a common corner cut.
It doesn't name its motherboard; a budget board can limit upgrades.
It doesn't list its CPU cooler; a basic stock cooler runs hotter and louder.

Time and skill: A first build takes about 3 to 5 hours with care: seating the CPU and memory, mounting the cooler, routing cables and installing Windows and drivers. No special tools beyond a screwdriver.

Our take: We could not price every part today, so compare again tomorrow before deciding.

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