Money mad Premier League spend £300 million in first week of summer window
By comparison, £870m was spent during the nine weeks of last summer's window.
Business analyst Deloitte expects gross outlay to rise above £1bn before the window closes on 31 August.
A new £5bn three-year television deal, which starts this season, is fuelling "unprecedented" spending amid "unreal" player valuations, football finance expert Rob Wilson told BBC Sport.
"There's no questioning the impact of the TV deal," added Sheffield Hallam University's Wilson, who said he had expected spending in the first week of this summer's window to be even higher.
Each club can expect to receive between £30m and £50m from the Premier League for 2016-17 as a result of the TV contract, under which Sky are paying £4.2bn and BT £960m for the rights to show live top-flight matches over the next three seasons.
Wilson believes that is driving player values through the roof. "We've seen this trend, over the last two or three deals at least, but we never thought the valuations would go up that much. It's unreal," he said.
The combined total spent by Premier League clubs over the summer and winter transfer windows last season was £1.045bn - up from £965m for 2014-15.
BBC Sport based its own estimate on actual fees announced by clubs and on reported figures when the value of a transfer has been undisclosed.
For a list of recent transfers use this link