Homeowners are paying more than €100 less for gas than last year, and prices are expected to plunge even further.
Price cuts over the year saw average annual gas prices drop from €910 in October 2008 to €795 last year.
And gas bills are expected to fall further in February, as an 8pc cut takes effect, taking €53 off the average bill.
But electricity prices are less favourable, with the average bill increasing from €736 in October last year to €795.
The opening up of the electricity market has seen 250,000 people switch to Bord Gais for their electricity since early 2009.
The company offers customers a 10pc discount on ESB prices and a 14pc discount when paying by direct debit.
Competitor Flogas is claiming it will always offer customers cheaper prices than Bord Gais for gas, and has guaranteed 9pc lower prices until February.
But consumer experts have suggested that if a household is getting its electricity from Bord Gais, it would likely be cheaper to stick with Bord Gais for gas too.
Saveafewbob.ie managing director Niall McHenry said: "Attractive offerings from both An Bord Gais and Airtricity has resulted in savings in the region of €100 to €150 for the average household."
The Irish natural gas market was opened fully to competition in July 2007, which means that alternate suppliers can compete against Bord Gais Energy in all market segments.
The electricity market was opened in 2005.
Homeowners have been enjoying increased competition in the domestic energy market over the last year.
Gas prices peaked in September 2008 at an average of €916 per customer.
Since then, there have been two reductions.
Consumers' Association of Ireland chief executive Dermott Jewell said it makes sense to review your electricity and gas supplier when there is such competition.