Oil change pricing question

[mountainman]

I have 3 porsches and drive each about 10K a year, so imagine my outlay if I went to the dealer for oil changes. I also change mine mor often than required ( I have had an IMSB failure in the past and try to do anything that may head of another one ). I do my own oil changes which just take a few minutes plus a liberal time to drain. I buy good german filters in quantity for about $9 each and buy mobile ! synthetic at advance auto or whereever when it is on sale for less than $6 a quart, so my oil changes actually run less than $60