With reference to the original question, it's a somewhat subjective calculation, but I would suggest it is considered as being comprised of four elements.
The Club seat is too narrow (although upper deck window seats are no problem), and could be touch longer, but is perfectly comfortable. The First seat has the extra space, in particular the elbow room.
The food in First is preferable, but, as you can expect better in a decent mid-priced restaurant, does not contribute towards the question of value. The wine, although downgraded in recent years, is greatly superior to the very average fare in Club, but again a couple of glasses of 4th growth don't go far in justifying the ticket price.
The cabins vary quite a bit. The 747 First and upper deck Club cabins are the best, next is 777 First, then the 747 main deck and 777 Club cabins, which are too busy with 8 seats across.
Finally you have what we might call snob value - you can put whatever weighting suits you on that.
Personally, I find the calculation relies on the type and flight involved. I don't like the 8 across seating in Club (was happy on day flights in the old cradle seats). So 777 - has to be First. 747 day flight - upper deck just as good as First (preferably 62 A or K). 747 night flight - First is best, but upper deck fine.
Anyone suggesting you should fly First to get into the Concorde room needs help.