Robart 615's
As I understand it Robart doesn't include the oleo strut or the the air support system in the price you mentioned above. A quick check on Tower and you'll find that an all up cost is more like $219.00. This includes the 615's($89) 650 oleo ($38x2) and the complete air support system ($53)
Sierra's price includes the oleo strut so basically you'll have to add the air support. Worth the price in my view. I've been down the 615 road!!!!
Mark