Solid enough, but will dependL
Which 450W Rosewill PSU specifically?
Sky & KabyLAke benefit substantially from dual-channel RAM (2x4GB) - although it would limit your upgrade options in the future.
Any reason for the R9 270? Unless you already own it, a 1050TI would be a smarter purchase.
I don't see any way that comes to only $339 unless you own the GPU?
Without a GPU, with a (very likely) better quality PSU which is only $27...... I come to $285 with no GPU
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel - Pentium G4560 3.5GHz Dual-Core Processor ($68.99 @ SuperBiiz)
Motherboard: MSI - B250M PRO-VD Micro ATX LGA1151 Motherboard ($61.99 @ SuperBiiz)
Memory: Crucial - 8GB (1 x 8GB) DDR4-2133 Memory ($54.88 @ B&H)
Storage: Toshiba - 1TB 3.5" 7200RPM Internal Hard Drive ($45.89 @ OutletPC)
Case: Rosewill - TYRFING ATX Mid Tower Case ($27.99 @ Amazon)
Power Supply: Corsair - CXM 450W 80+ Bronze Certified Semi-Modular ATX Power Supply ($26.99 @ Newegg)
Total: $286.73
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-06-21 14:33 EDT-0400