I'd rather think of Calde (free) Bruno (free) Greer (just a few thousand) Orlandi, Lopez etc All managers have flops, but generally Poyet was in credit. There were others wasting money excessively, so don't point the finger in just one direction.
Nothing to do with John Stephenson bringing in Roland Bergkamp, Burke bringing in players that he didn't want either? Ken Brown was spending money like water too. All of whom got their marching orders very smartish, although one took longer than the others to get found out.