An i3 would be sufficient for a home office machine. There is no way you need a 6600k and definitely no need for a 950 Pro. Something like this would be sufficient:
PCPartPicker part list / Price breakdown by merchant
| Type | Item | Price |
|---|---|---|
| CPU | Intel Core i3-6100 3.7GHz Dual-Core Processor | $112.99 @ SuperBiiz |
| Motherboard | Gigabyte GA-H110M-A Micro ATX LGA1151 Motherboard | $51.89 @ OutletPC |
| Memory | Kingston HyperX Fury Black 8GB (2 x 4GB) DDR4-2133 Memory | $39.99 @ Newegg |
| Storage | Samsung 850 EVO-Series 250GB 2.5" Solid State Drive | $87.77 @ OutletPC |
| Storage | Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive | $47.77 @ OutletPC |
| Case | Corsair 200R ATX Mid Tower Case | $49.99 @ Micro Center |
| Power Supply | Corsair Builder 500W 80+ Bronze Certified ATX Power Supply | $29.89 @ Newegg |
| Prices include shipping, taxes, rebates, and discounts | ||
| Total (before mail-in rebates) | $450.29 | |
| Mail-in rebates | -$30.00 | |
| Total | $420.29 | |
| Generated by PCPartPicker 2016-04-09 15:15 EDT-0400 |
If you want to spend a bit more you could get a better quality PSU (the CX series are of mediocre quality but will be good enough for office machines) and an i5 but the current build would be perfectly fine.