50k could be ok if you are already here. But coming here as a foreigner and taking the risk. Heck no...
Here's why:
1) you need to give up your current stable job
2) you need to sell/cut ties with your current life (home, car, furniture's, etc)
3) you need to pay for 3.5 month's rent up front when you get to HK. You lose this if you lost your job or decided you wanted to leave suddenly.
4) you also need to pay for furniture's for your new flat, so there's considerable cash you need to get started when you land in HK
And 12-15k but you thought you would be in 600'? Where's the LOL. 12k studio is less than 200 sq ft and the bathroom so small that you shower over your toilet. Sound interesting to you? It's disgusting...
Do you want new or old (paint falling off walls, lift seems like it will break every time up and down, you'll soon be on here asking how to fix or address these things, short answer, deal with it)
New studios/1bed 20-25k per month in a legit building with a good location. 30-50k will get you something decent, size wise, probably with old decoration style. You won't be a baller even spending that much in rent so don't think that.
Now yes many people live in cheaper flats or further away. That's great but when you first arrive I recommend to live in a central area for the first year or two then move once you've had time to explore. Cheaper flats will have some problems, not new, low floor, water leaking, too hot in summer, mass murder in your flat, bad Fung Shui (many people believe in luck and that having good luck at home can give you better fortune here - I believe). Don't try to save a few thousand to add daily headaches to your life. Time is valuable.
With that being said.
You will want 50k basic, defined bonus structure, 20k minimum rental reimbursement. Then look for apartments in the 20-30k range.
If not, say no and move on.