I think it is worth the price. I found my first CFI job there.
I am about to go to a new job, but if I don't make it at the new gig, I already have a back-up choice I will apply to which I found on 350 and would not have known of otherwise.
I have seen many jobs I could have applied to as my hours grew, but I stayed at that first job pretty much because I have other obligations that meant I needed to stay where I was geographically. But for someone else who is free/willing to relocate as needed while your career develops, I think you will find plenty of opportunities on the site for low time. The opportunities can be cyclical, depending on the time of year. It seems like many of the sub-1000 hour jobs run through hiring cycles every 4 months or so. For example, the Grand Canyon air tour company that might hire at 500 hours, or some Alaskan companies, who look for folks in the spring to cover summer and fall season.
Another aspect I like is that I am exposed to listings for many companies I never heard of before that might be I interested in later, when I have more hours/meet the reqs. I have also learned a lot after seeing a job link, which gave me a starting point to do research on a company or type of flight gig that helped me figure out what kind of flight job I would really like to do. Or what companies/jobs to avoid in other cases.
You can probably find most of these companies on your own and do all the same stuff other ways, but that will take more effort and time to do it yourself. How much is your time worth?
As
@Sosee sort of said, you can always apply to a company and even if they say no, at least you have just initiated contact with them/ introduced yourself to them. That could lead to opportunity down the road if you follow up later when you meet their requirements.
Once you find a gig, you can stop your subscription and leave all your account info and resume, etc on the site until you need to hunt for the next job. Pretty sure you can still get to your personal stuff while your subscription is inactive too, if you need to download it.
So all that for $80 a year or so? That's at most a couple hours of CFI work. Easy to justify the cost I think.