The word "afford" can mean many things to many people. I've done ex-DUB before (and also ex-AMS) when it would get me business class for roughly the price of WTP ex-LHR. Other times I haven't found a deal of that kind and have prioritized saving money just by flying WT/WTP from LHR over flying in business. I personally would consider 5% of our household income to be unreasonably steep for a plane ticket when we can save the money for a purchase that will last longer or for retirement. So in my household we only started even thinking about ex-EU business fares once our income had reached a level where it would be closer to 1-2% and by this standard ex-LHR CW still is prohibitively expensive for us. But OP draws the line in a differently place, and that's entirely legitimate. It's a matter of personal comfort and how one values one thing versus another when it comes to all the things we can spend money on.