I went from 3x to 1x about six months ago on my hardtail. My cassette was starting to look pretty worn so I thought I'd do the lot in one hit. I purchased a 30t narrow/wide chainring for about $40, replaced the cassette with the same 11/36t and a new chain, all up I roughly spent $130. But if everything else is in ok nick, I'd just chuck on a single ring and give it a crack to test it out.
I mainly ride rail trail and dirt roads near me so I'm not chucking the bike around much. I'm still running the original long cage non clutch rear derailleur, but I haven't dropped a chain at all so I don't think I'll bother with getting a clutch rear derailleur at this stage. I'm happy with the setup, not really missing any gear range for the area I ride, the bike looks sleeker with less stuff on it and its easier to clean the crud off 1 chainring.
Just do it.