The price of petrol I paid during September 2020 averaged $1.27 per litre for 91 Octane unleaded petrol add up to 15 cents more for 95 Octane petrol and usually up to 25 cents for 98 Octane petrol, location is Melbourne Australia.
The price of diesel was around $1.22 the last time time looked and this the price does not fluctuate much compared to unleaded.
Note that fuel prices vary according to area, the level of competition and a whole heap of other factors like shopping discounts and so forth, however unreasonable high prices (relative to crude oil prices) is greed. Also note that the Octane level I post here represents Australian measurement which is different from those in other countries eg. US.
Apart from the actual prices I paid at the servo the websites I use to research the crude oil pricing are: