As far as I am aware, Moysie is given a budget that allows him to spend £10-15M on a single player every summer. This is shown by using signing Johnson - £8M in 2006, the Yak - £11M in 2007 and Fellaini - £15M in 2008. This trend suggests that this budget is increasing every summer although of course not all the Fellaini money will be paid up-front. By adding a quality player worth that sort of money every year for 4 seasons in a row should be enough to build a core squad (not including injuries) which could challenge. Therefore on this logic, a big-signing this summer could be enough to force us in there. However this does not take into account other teams' spending so therefore I would suggest that the only way to get into the top four is if Man Shitty, Spuds and Villa struggle and one of ARSEnal or the kopites have a bad run.