There are details on the ICOM, UK site about the IC7300. It is my view this radio is overpriced and I expect the price to be slashed later.
I think it will be head-to-head against the Yaesu FT991A and the IC7300 could easily be sub-£1000 in the UK because of its architecture. If the FT891A is retailing at £699 in the UK, then the IC7300 can be less expensive. I know they are very different radios, but the dealers charge what people are prepared to pay. Too many are prepared to pay inflated prices.
See http://www.icomuk.co.uk/IC-7300/Amateur_Radio_Ham_Base_Stations .