Guys sorry amateur here,only branded brands are being discussed?
if not, here my story..on my pre-plan to get myself a specs

i went to Pearle vision at SS15 Subang Jaya
told that guy my budget say 300-400
he then showed me this specs, which i kinda like it
not sure about its brand name..but saw a couple of keywords by its side Jpu 01,140,made in korea or was it japan, +Lab
after his typical aka kononnya give me discount on the specs after randomly pressing his calculator , he says best price is 480

i don't know where to begin, how much of bargain can i actually ask for?
the label on the specs itself shows 480 and then he said best price is 480?

any advice on what should i do from here?
like = terus buy?
what should i check on?,what should I notice? what do I look for?...etc?

am just looking for a well, need not be the most trendy of specs..just something decent..for my everyday use..driving/watch tv etc

i thank you in advance for any advice