Filled up at the Plenoil station in Santa Pola today, diesel is €1.119 at the moment, a bit more expensive than when the OP visited but still the cheapest fuel I've had anywhere on this trip other than Gibraltar. I rolled in on fumes and brimmed it so I'm a happy camper. There is "Gasexpress" station across the road with diesel at exactly the same price. GPS for these two stations is 38.19879, -0.56770
Just up the road is a Cepsa station which has LPG at 62.6 cents/litre. 38.19721, -0.56205
Now parked up a few miles away adjacent to the beach at Monte Faro. "No camping" signs but it appears not to be enforced, there are about 50 MHs here. 38.22666, -0.51087
Cheers