Yea well tell that to those who have a hard time filling up their tanks to get to work, to the store or to simply go to the park
Several cheaper alternatives there: Walk, Cycle, Bus/Coach, Train/Tram/other public transport
The price of oil in the US is also about half that of the UK, and I don't think UK incomes are twice that of the US's, so it's not like people would be unable to cope. Furthermore, if the government was to increase the price on oil via a tax, that would generate revenue which could then be used to provide benefits/assistance to those people on the lowest income who would then be struggling. Alternatively the revenue could be used to subsidise more energy efficient methods of transport (hybrid cars, or public transport), or to subsidise renewable energy.
Re: Obama's message of change though, the good/bad (depending on who you are) thing about it is that it doesn't specify just what that change would be, but rather leaves it to the listener. So you can end up with lots of different people all thinking things will change (in a way that would be good for them) - it makes it an effective message, but could lead to some disappointment post-election (at least for those who simply vote based on that message, rather than looking into more detail about what policies that change might entail)