Depends on your local market. Around here, that bike would not last for a day on CL at $180. But most likely someone would be commuting on it rather than taking it to the trail...

I wouldn't put any more money into it, and I wouldn't expect to get $180 back out of it... but yeah, I think you could check out singletrack with that. And then let's be honest, most likely if you like MTBing, you'll want to upgrade soon.