Why... if you have the money to buy a new pc and it doesn't affect your long term financials (ie not going into debt) then I don't see what the issue is (other than paying higher prices than we'd all like).
Yes times are tough and we all need to make logical decisions about how we use our money but that doesn't mean we should feel 'guilty' if we do spend some money on something 'pleasure' orientated (lets be honest, at the rate things are going we're all likely going to be home more because restaurants etc will be closing due to electric/gas costs).