It surprises me too.
We only paid a transfer fee for 3 out of the 17 that came in (Robinson £1.5m, Etete £500k and Tanner around £40k), but there may have been loan fees and 'sign on fees' for a few out of contract players.
Overall we slashed the wages from the year before (down by 30%+ I think from the figures discussed here last month), with a reduced average salary target, but no-one really knows the individual wages of the incoming players.
The Athletic did a review of summer 2022 Championship transfers and claimed that a few relegated clubs were spending a lot to restructure (though Norwich held on to most of their Premier League squad) but a lot of clubs were totally reliant on frees and loans (although they too could have paid loan or signing fees):
https://theathletic.com/3561377/2022...ndow-round-up/
As the summer underlined, this is a level increasingly dominated by transfers without cost. Championship clubs signed 65 free agents this summer, almost three apiece, while also agreeing to 79 loan deals. It is hard to be clear in the age of undisclosed fees, but it is estimated that only 47 transfers required a sum to be exchanged.
Reading, who remain the only EFL club operating under a transfer embargo, were joined by Bristol City, Coventry City, Queens Park Rangers, Rotherham United and Stoke City in dealing only in loans and free transfers. Preston North End and Wigan Athletic, meanwhile, only parted with nominal amounts.
That puts our spending above 8 other Championship clubs - but doubt it puts us very high in the spending league.