why would you pay someone to grease/pack your bearings? it is not that hard to do. 500 miles is not really any miles on the bearings. You have the zerks on there, just gently pump one or two handles in it and sleep well. Use grease that is made for what you are doing. My last camper I had for more than 16 years (averaged about 5-7,000 miles per year )and only pulled the bearings out twice in that time and hand packed them. Never had a problem with bearings.
2013 Forest River Salem Hemisphere SBT312QBUD
2001 CrewCab F-250 7.3 PowerStroke Diesel
SuperChip, BTS transmission, 6.0 Trans Cooler