I have read the last 28 pages (whew!) :) Really interesting thread.
Like some other quilters on this board - when I first started quilting I bought gadgets. As time has progressed, so have my circumstances and quilting experience. I prefer a more simplistic and uncluttered lifestyle (which is translated into my quilting experience).
When thinking about notions that are a waste of money - I've had to think about which items I have that are useful but I don't use often, or that a really a waste of money, e.g. I would throw them out (or give to someone else to try).
So... most of money wastage has been on quilting marking tools. I would not buy "fat" quilters pencils again (you can't buy sharpeners big enough). I would not buy clover chalk pencils the ones with the wheel inside (because my designs are more fussy/detailed (this tool is great for straight lines or bold long patterns). I would not buy "washout" blue pens. And finally I would not buy crayola washable markers (they didn't wash out when I did some tests).
What I did buy that works for me - is a mechanical pencil by SewLine (similar to Fons and Porter)
http://www.sewline-product.com/Sewline_Trio I have also purchased additional refills (grey, pink, green, yellow, white).
I haven't gone crazy rulers. I only have 3.
I have gone crazy on Marti Mitchel templates. If I was going to do it again - I wouldn't buy so much.
All my other equipment is tried and true. Usually based on friends recommendations. If they a local I have tried the products first before buying. That is what I did with my silver cone thimble.
http://www.thimblelady.com.au/catego...ools/Thimbles/ My stash of threads and needles are "core" and basic (unlike my fabric stash - but that's another story).