I do not want to argue about what people should spend or not. Let me first clarify one thing that may have been lost in translation, however: the 800 pounds was for two people and not one as in your example. The quality/cost level that I chose by way of example of traditional gear was typical of what many Dutch couples would use and was chosen for that reason.This is good gear that will last 10-15 years. My argument was that by getting (much) lighter stuff one could get kit that was at least as good and at least as comfortable as that traditional kit, but for rather less money. At a cost of some 50-80 pounds per year it is, therefore, very good value, I think. The Dutch text also includes a discussion of using what you already have or could borrow (and there is plenty of good second hand stuff). That is quite relevant because in Holland many people already own camping gear (and do not need persuading that camping is fun). The only thing they may not have is panniers. The text argues that you may need less than what the shops try to sell you, and that investing in compact sleeping kit is worth the money. Each year I give presentations at annual fairs on cycle touring such as the one in Amsterdam that draws more than 20000 visitors each year (yes). If there is one thing that strikes me time and again it is the belief by many inexperienced people that they need all this stuff that is pushed so hard by the trade.
In a different line of argument, I am always a bit surprised that many people think nothing of staying in B&B's and hostels, or eating out in pubs, but frown on investment in good gear. 800 pounds is an investment in camping gear you can earn back in perhaps two longish summer holidays. And yet it will last many times longer. So I still maintain lighter is not more expensive than the equivalent traditional kit, and that investing in quality kit is one of the better investments you can do.
Willem