15k Rent on a 50k salary is 30% before tax income on rent. Which is reasonable if you ask me. And given the net income after rent is still above 30k, its still more than enough to enjoy a decent bachelor lifestyle. Technically, your net income is higher than most locals around 30.
Just keep the hooker and blow to a minimum
Edit: on a serious note
Try and find a place with convenient commute. Just because it is the same commute time, does not mean the experience is the same. Ie. waiting for a minibus in 35 degree weather or black rain is not fun.
Id suggest commuting via MTR since it is the most newbie friendly method. For best rent to size value with MTR in mind, I would suggest eastern HK island (ie. Sai wan ho all the way to Chai wan). The commute will be under 1 hour including walking and it is just one train line. Ive lived in eastern HK island and I loved it. Since you arent going to bars/clubs, Eastern island gives you easy/friendly work commute and reasonable rent value.