It's actually fun to educate people on diamonds haha (if they are not brand-focus)
I myself used to be brand focus back then as i didn't know much about diamond....every branded diamond looks bling to me. I've personally gotten Tiffany, Celestial, Brilliant Rose and was considering on Royal Destinee until someone told me about Jann Paul then i finally researched more into diamonds.
I was skeptical at first and did some searches for other similar concept stores too (e.g. bluenile, james allen, whiteflash, brian gavin), in the end i came to a conclusion that yes, JP price might not be the cheapest among all the online stores I've mentioned, but it is definitely the strictest super ideal criteria I've seen so paying 2-3% (based on my previous comparison) premium more to guarantee a higher quality diamond with local free resizing, polishing & upgrade plan seems to be the most rational choice to me.
As for other Singapore diamond stores with similar concept, TBH, i don't find any of them come close to JP in terms of quality nor pricing.
Some people might think it's impossible that how can they sell high quality diamond yet cheaper than the rest of the competitors and still profitable...they might want to look at it in business point of view....
1) Jann Paul is sharing the same shop front as House of Hung whom is in jewellery trade for decades
2) They are related (father and son) - not surprised if their rentals are waived or heavily subsidized

3) Tap into HOH's resources on vendors, diamond sources etc (Probably get a good pricing as compared to other less experienced jewelers)