PCPartPicker part list / Price breakdown by merchant
| Type | Item | Price |
|---|---|---|
| CPU | Intel Xeon E5-1630 V3 3.7GHz Quad-Core OEM/Tray Processor | $364.99 @ SuperBiiz |
| CPU Cooler | CRYORIG H5 Universal 65.0 CFM CPU Cooler | $46.99 @ Newegg |
| Motherboard | MSI X99A Raider ATX LGA2011-3 Motherboard | $181.49 @ Newegg |
| Memory | G.Skill Ripjaws 4 Series 128GB (8 x 16GB) DDR4-2800 Memory | $699.99 @ Newegg |
| Storage | Sandisk SSD PLUS 120GB 2.5" Solid State Drive | $39.99 @ Best Buy |
| Video Card | XFX Radeon HD 5450 1GB Video Card | $27.99 @ SuperBiiz |
| Case | NZXT S340 (Black/Blue) ATX Mid Tower Case | $63.99 @ SuperBiiz |
| Power Supply | Rosewill 550W 80+ Platinum Certified Fully-Modular ATX Power Supply | $72.00 @ Newegg |
| Prices include shipping, taxes, rebates, and discounts | ||
| Total | $1497.43 | |
| Generated by PCPartPicker 2016-04-16 15:15 EDT-0400 |
I doubled your RAM, got a better PSU and went with an air cooler.
I would use YAMS which is a Mine craft server software that claims it can run the minecraft server in a multi core mode.
Too be fair, I have no idea if this will run a minecraft server for 1500 people. For those types of servers, hosting companies use multiple servers and combine them with BungeeCord.