my local dealer has a deal where you can prebuy packs of 3 oil changes; the 3 packs are significantly lessblown away that it cost $160 for a basic oil change.
For example, on my ecoDiesel a single oil change was $260 but a diesel pre-paid 3 pack is $310 after tax; so, $103 per oil change and the ecoDiesel oil/filter would run me $85 on their own.
Not sure what the RHO cost will be.