If you have a mobile RV repair service within a reasonable distance of you, find out what they would charge to repack your bearings. My local guy is only 3 miles away. I used to do my bearings on a single axle trailer we had, but I didn't like doing them. Now that we have two axles, I really don't want to do them.
My local guy charges $55/wheel. That's $220 total. I can get them done cheaper, but I have to take the trailer to them. This guy does it right in my back yard. I just get them done every other year, though, since we don't travel great distances. When I had the bearings done the first time, he climbed up on the roof afterwards and showed me how to check for areas that needed caulking, and how he does that. He went over the whole roof with me with his tube of Dicor and touched up any suspicious areas. No extra charge for that, even though that service is normally extra.
If you can learn to do most things yourself, you can save a lot of money in maintenance. I choose to spend money on the bearings, but do everything else myself.