That sounds expensive for powder coating. I got all mine done for £120 although didn’t include my wheels as they are spoked. Wheels up here are around £60 a pair.
There is a spacer in between the bearings. This is a tube and has a collar at one end. The collar is to help hold the spacer concentric with the I/D of the bearing so they line up for the axle to pass through. The tube is trapped between the bearing inner races. You need to insert a metal bar through one bearing and the tube but NOT into the other bearing then lever the tube sideways to expose the inner face of the bearing giving you a face to drive it out. If the tube doesn’t move it will be because the collar is at that end so try from the other end.