I have an Intel 5820k for sale. This chip is used but has been well taken care of. No excessive voltage or heat, and it has been watercooled its whole life. I really hated having to replace it but I needed more PCIe lanes so I replaced it with a 5930k just a day ago. I have the original matching box as well.
This chip overclocks extremely well and will run 4.5GHz with 100 BLCK (Multi 45x) @ 1.33vcore. I can provide you will all the OC settings and if you have a Rampage V Extreme I can provide you every little OC setting I used with BIOS 3301. Cache will OC to 4GHz @ 1.325 and possibly higher however I never pushed it past 4GHz.
At 4.5Ghz this chip is a little finicky with RAM and I topped out at 2800 (RAM rated at 3200), however your results will be different depending on memory type. This is with training and enhanced training enabled as well as all memtests at POST.
These Haswell-E chips are better than the newer Broadwell-E IMO, they simply just overclock better and this is why I replaced this chip with a 5930k and not a 6850k. The retail price for this chip is $390.00 and I feel accounting for silicon lottery this chip is worth $325 with shipping via PayPal.
PayPal - Confirmed address ONLY
Amazon GC - Take off 4% ($312) - Can ship anywhere.