Haha unfortunately i am one of those "fad" buyers, i HATE neutral pieces and believe that EVERY outfit should be fabulous so would rather invest in fantastic designer bags and then use cheaper but special pieces for my clothes, shoes, accessories, etc....
I do think that the Kain pocket tees and tanks are great wardrobe staples though and have such a better look about them than regular tanks and tees,
Also Miu Miu and Lanvin flats are worthwhile splurges as the heels won't wear down like stilettos and they add an extra piece of glamour to everyday outfits,
Tolani scarves are also a great investment, the styles and lengths are TDF and do last,
As for jeans, well TBH i don't buy into expensive denim as my River island jeans fit perfectly, look great and last for ages and look good after many washes so i do wonder WHY pay extra for designer denims?
I would rarely pay out for designer high heels either, for the fact that unless they are for a special occasion then it is just silly money as after 2 or 3 wears they will need re-heeling, why bother when i can get highstreet shoes that are just as gorgeous and cheap enough that after a few wears i can throw them away? I get the added bonus of never being seen in the same shoes more than a few times so my shoe collection is constantly updating
If you are into leather then i think a great leather jacket is a must investment, personally i don't do leather jackets but for those who do - definately invest in something like a Rick owens that will last and last,
Jewellery i think comes and goes but is also a great idea to invest in classic pieces like pearls, diamond studs and small hoops - in whatever gold/silver/platinum of your liking,
Hope this helped