If booked within the promo period, it would earn triple base avios (so around 1,400 extra avios for CE or Y/B/H, vs. 350 for O/Q or 700 for N/S/V/M/L/K), plus the full base avios + cabin bonus (so another 700 or 875 of difference).

I'd value the avios at around £14 assuming it wasn't the very cheapest fare originally.
A snack/drink budget of £10 isn't unreasonable.
£30 for luggage makes a difference - and I believe that putting CE one way means that your luggage is paid for in both directions assuming that the return leg is on the same ticket.

TP value is essentially zero on the last day of your year.

So all in all, it is possibly worth doing - I probably wouldn't go for it myself apart from the luggage, and definitely not if I had an exit row (whcih I usually do, to be honest!) But it's not a complete no-brainer.

If you get your luggage paid both ways then that, plus the avios and the on-board service pays for the upgrade so I'd go for it.