Next there's a report at TechPowerUp with pricing of six Coffee Lake desktop processors. All prices include VAT.
Core i3-8350K: 199 € Core i5-8600K: 299 € Core i7-8700K: 419 €
These prices originate from an unknown shop so we don't know how accurate these prices are. At the moment, they seem a bit higher than the current Kaby Lake models but we'll have to wait a couple more weeks for more reliable information.
Core i7-8700K: 389EUR Core i7-8700: 327EUR Core i5-8600K: 273EUR Core i5-8400: 192EUR Core i3-8350K: 188EUR Core i3-8100: 123EUR
The official launch date of Coffee Lake-S is October 5, 2017.