That's the main reason why Fulham now find themselves struggling. Fayed bankrolled them a lot in their first Premier League season, but thereafter they largely operated on a shoestring, initially so Craven Cottage could have work done to it and then in later years when Fayed seemed to lose...
Burnley can't just go out and spend £15-20 million on new players, they don't have that level of investment and the gates they get at Turf Moor aren't conducive to that happening. Therefore they have to stick to the principles that got them promoted in the first place, most crucially their team...
In the event of Burnley getting promoted, I would expect Dyche would want to keep as much of that squad together as possible. As much as Danny Ings and Trippier have been exceptional, the unity of that squad is the reason for their success this season.