Can't really comment on the Sussex league currently as the only time I see those sides now is in the Sussex Senior Cup(s) however SCEFL (what was the Kent league) the standard is far from average IMO.
Crowborough who's troubles have been well documented this summer had a side full of players...
Lots of players at step 5 (county league one in old money) have agents these days.
The big spenders even at that level will have a playing budget of £2k+ a week.