An option for you depending on mobo is going the Xeon route. Starting with the e3-1245 v5 is rough equal to a 6700. Around $60 on ebay. 1270/75/85 are like 3.6ghz with boost at 4ghz. Xeon V6 is Kabylake but they seem to go for a lot more on ebay, basically same as 7700k prices...
Via a presentation in China, Sept. 15th is launch date for Ryzen 7000 series.