I must admit that since feb 2012 I haven't been taking the RRc out very much so I'm a little out of date on LPG, but at that time LPG moved from about 30 percent the price of petrol to about half because of excise. What did get to me was that traveling from Sydney to Nowra I found the change in price between Sydney and Albion Park was about 12 cents/litre for both petrol and LPG.
The issue was that for petrol it was a 10percent increase in 70km but for LPG it was a 30percent increase which was far in excess of the actual cost of transporting the fuel and IMHO it was a case of price gouging.

