Yes, Ebay is the way:
Almost unused headset (for pax/spare use) £40, £110 new.
Sporty's E6B electronic calc, £24, about £70 once imported or equiv. here.
RNAV plotter, £2, £7 new.
IMC DVD, £12, £28 new.
& so on. (All the above include postage too).
Plus a few books at 1/3 to 1/2 price.
Just don't get caught up in the bidding, check out the new price before you bid. I've seen several examples lately of folk bidding more for secondhand than new!!
Amazon is worth checking out too as you can get used books for a pittance, although be aware, as Ebay, if they need to be up to date editions, the ones on sale may be out of date.
Even some brand new books can be £'s less. eg: T.Thom book 5 (IMC etc) £25 from most places, under £18 incl. post from Amazon brand new latest edition.
Remember, being tight with you money is not a problem.....
It's an art-form and a talent!!!!!