Build a mining rig or just buy the coin?

I’m fairly new to crypto and mining. I’ve been enjoying mining RVN on my 1070 gaming rig for the past few weeks. It’s a meager wage at 16.1 MH/s, but passive income is passive income and the future potential of RVN is exciting.

I’m interested in maybe building a 6x RX 570 rig with some second hand cards. I almost pulled the trigger but then got cold feet when the thought hit me that just buying RVN in an equivalent amount to what a rig would cost me would probably be a more wise decision since I don’t have to wait 6 months at the current price to break even. Not to mention the potential for the network difficulty to increase between now and the theoretical break even point seems high considering the migration of ETH miners and recent price spike.

Now don’t get me wrong, mined or purchased, the plan is to go long and hodl for the long term. Can anyone with extensive mining experience tell me what I’m missing and why I should jump in to a build? Mining is rewarding psychologically to me and I’d love a good excuse to start a project but at this point I’ve almost talked myself out of it.