Is this a good idea ?

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-7700K 4.2GHz Quad-Core Processor (€360.95 @ Mindfactory)
CPU Cooler: Corsair H100i v2 70.7 CFM Liquid CPU Cooler (€109.85 @ Mindfactory)
Motherboard: Asus STRIX Z270-E GAMING ATX LGA1151 Motherboard (€219.85 @ Mindfactory)
Memory: Corsair Vengeance LPX 8GB (1 x 8GB) DDR4-2400 Memory (€74.67 @ Amazon Deutschland)
Storage: Kingston Predator 240GB M.2-2280 Solid State Drive (€180.87 @ Mindfactory)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive (€75.78 @ Mindfactory)
Video Card: Gainward GeForce GTX 1080 8GB Phoenix GS Video Card (€719.99 @ Aquatuning)
Case: Thermaltake Versa C22 RGB ATX Mid Tower Case (€68.90 @ Amazon Deutschland)
Power Supply: Thermaltake 650W 80+ Gold Certified Fully-Modular ATX Power Supply (€144.00 @ Amazon Deutschland)
Operating System: Microsoft Windows 10 Home OEM 64-bit (€99.85 @ Mindfactory)
Case Fan: Thermaltake Riing 12 RGB 48.8 CFM 120mm Fans (€88.90 @ Amazon Deutschland)
Total: €2143.61
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-02-20 02:37 CET+0100


About part for part the same specs, seems about what you could build it for yourself, but not much less, so if you're not comfortable building yourself, doesn't seem like a bad deal.
 
Solution

That's actually pretty good. includes watercooling. faster m.2, good psu n 3 years warranty.
good choice.
P.S. if u r building a pc, then u can actually go for 1070 sli for the same price 😉