The hardware may be more expensive, but due to things such as the frequent sales on steam the software actually comes out being much cheaper. When you factor that together the rift between the two price wise is very small. Nowhere near what you are implying.
the argument is not stupid but based on numbers and a bit of calculation. its been true 5 years ago and will be true the next 5 years.
except, of course, by gaming you mean playing solitaire and hearts on an old windows pc.
It is stupid. If I'm going to buy a powerful desktop over the course of time anyway, why the heck would I bother buying a powerful desktop capable of what I want to do, AND a gaming console? My spending limit on graphic cards is around $130-140 anyway. I'm running a 9800GTX still for instance, and I'm still playing Battlefield 3 at better resolution and settings as a console... I bought this back in 2008 too.
TL;DR: It's not as expensive as you think. Besides, I can't be bothered with Live subscriptions, $60 games at release, hell I don't even have an HDTV yet!
It's not worth arguing they wont listen. PC master race gaming at max detail can't be done on one spec of PC through the 10 year life of a games console. You are going to have to upgrade at LEAST twice in the course of a console lifetime with a new graphics card, new processor, more memory, etc.. at least $/£500 a time.
Or you can buy a $/£300-400 console and be able to play the latest games for 10 years.
You're acting like no one has purchased a PC anyway over that time though. Maybe today that would make sense in the age of smartphones and tablets, but many of us have some sort of computer... Let's quit playing make believe.
Even if I wasn't a PC gamer, I'd still have bought 2 desktops since 2004 anyway given their life expectancy...