The difference is subjective, you will never be able to "prove" it. However, that doesnt mean it's not real or "worth it". There are a ton of products out there like this:
-all wine is made with grapes, so why not just buy the stuff in the cardboard box?
- All jeans are made of denim, so why not just buy the pair at K-Mart?
- All soap will get you clean, so why not buy the store brand?
IMHO if you live like that life is very dull. If you only purchase items that you can "prove" are less than cheaper items - you will just end up with a bunch of cheap stuff.
Ive use $15 waxes (Nattys / Megs / Zymol OTC liquid) and I've use $100+ waxes (Zymol, Fuzion, Souveran, etc...) and the higher priced ones always seem nicer to me. There is nothing wrong with cheap waxes, just like there is nothing wrong with more expensive ones if you can afford it. I can tell you spreading Glasur just feels like luxury - you cant quantify it.
Cheaper waxes use cheaper solvents (natural vrs "chemicals"), cheaper scents, cheaper packaging, and cheaper ingredients overall. If you think a $45 jar of Auto Finesses' Temptation is exactly the same as a $200 jar of Soul (except the color and label) - I think that's being a bit too skeptical and naive.
Why not splurge and try some, you may like it?