Assembling a computer [HELP]

And so, my friend, I was about to assemble a new computer t.I’m no longer happy with mine, but that’s not the problem, I don’t understand this, I dug up all these systems on the Yandex market. If somewhere you can save money or choose something better, then write your options here. I would like to collect for ~25,000 rubles.

Current system:

Case: X
CPU: Intel Core 2 Quad CPU Q6600 @ 2.40GHz (4C 2.4GHz, 2x 4MB L2)
RAM: Samsung M3 78T5663QZ3-CF7 2GB DIMM DDR2 PC2-6400U DDR2-800 (2nd)
Video card: NVIDIA GeForce GTS 250 (128 SM4.0 1.62GHz/1.84GHz, 1GB DDR3 2GHz 256-bit, PCIe 2.00×16)
Motherboard: ASUS P5KPL/1600
Hard drive: Seagate ST3500320AS
Power unit: 🙁
OS: Windows 7 Ultimate 32-bit

First option:

Frame: Thermaltake Commander MS-I https://noidverificationcasinos.co.uk/review/betfoxx/ Snow Edition VN40006W2N White — 2267 rubles

computer case Midi-Tower
without power supply
for ATX, mATX form factor boards
Front connectors: USB x2, including USB 3.0, headphones, microphone
material: steel
dimensions: 202x426x484 mm
weight 4.5 kg

CPU: Intel Core i5-2500K Sandy Bridge — ~7000 rubles

Quad-core processor, Socket LGA1155
frequency 3300 MHz
L2/L3 cache size: 1024 KB/6144 KB
Sandy Bridge core
32 nm process technology
integrated graphics core
built-in memory controller

RAM: Kingston KVR1333D3N9/4G (2nd) – ~ 900 rubles

1 DDR3 memory module
module capacity 4 GB
DIMM form factor, 240-pin
frequency 1333 MHz
CAS Latency (CL): 9

Video card: GIGABYTE GeForce GTX 550 Ti 970Mhz — ~4000

PCI-E video card NVIDIA GeForce GTX 550 Ti
1024 MB GDDR5 video memory
core/memory frequency: 970/4200 MHz
SLI/CrossFire mode support
DVI, HDMI, VGA connectors
support DirectX 11, OpenGL 4.1
working with 2 monitors

Power unit: Some kind of 600W — ~ >2000 rubles
Motherboard: ASUS P8Z77-V LX — ~ 3500 rubles

motherboard with LGA1155 socket
ATX form factor
Intel Z77 chipset
up to 4 DDR3 DIMM memory sticks with a frequency of 1066 – 2400 MHz
CrossFire X support
expansion slots: 2xPCI-E x16, 2xPCI-E x1, 3xPCI
SATA 3Gb/s connectors: 4, SATA 6Gb/s connectors: 2