Fraser,
For the ebay part, send the link of your found treasure to the forum and mentally treat it as if you have bought it. This may sound illogical or silly. But after I have a "spend list" that rank the priority for my dollars, the hobby items still get added to the list, but seldom risen up in priority for them to be bought. Writing them down, thinking how they are going to be used, etc etc are not the same as actually owning them, but can be very satisfying and definitely reduce the guilt factor by a lot.
I always enjoy your posts, and also learn a lot from them.