I was thinking about this when picking my FPL team, having Hazard and Costa seems like a bad move I'm not sure how often they will both be on fire at the same time.
Cesc will have a good season no matter what.
Hazard and Costa are both penalty takers and will play 95% of games in one of the top 2 sides. Based on this line of reasoning, it's worth the investment... But there is bound to be frustration along the way as it's a Mou team after all.
Fabregas will be solid but he's going to be in the center of midfield, so I'm not sure just how many touches he'll get in attacking areas. I'd love to swap Hazard out for the cheaper Fabregas, so I'm hoping he shows himself as a big player.