You'll be sitting forever in the Kay NM lobby as an ilevel DPS without a support friend. Realistically at the 1540 ilevel this content can go from 1-2 hours depending on what happens in Clown or Brel G4.
The combination of Clown/Brel NM/Kayangel is around 16K if you count the Brel G4 gold.
The collection of those three raids would pay out around 11-12K gold, rarely take more than an hour per character unless someone was an agent on portals, and had minimal gatekeeping at 1472.5 with 4x3 (which was what, a 10-20k investment?).