I have had a sales rep from Shaeffers Oil stop at my shop a few times. He talks a good game and his products sound good but are they? Also he is quoting me $11.50 a gallon for a Para Synthetic 1540 is that the going rate or is he trying to over charge. It seems kinda High. It is more money than my current oil and don't know if its worth it. any input would be appreciated. Thanks Larry