We bought good quality LEDs in China in quantities of 1000+ for ~US$0.03-0.07/ea for 5mm single color, so this price is low, but not so low that I would suspect a scam. I wouldn't expect top quality though - but they do claim to be new. Maybe you want to get a few small packs to try first.
They seem to have a very narrow light beam because the case focusses it. Is that what you want?
I bought some cheap LEDs from a surplus store. Half of them did not work.
All my Philips Luxeon Lumileds work perfectly and are very bright over a wide angle.