You still need a chainsaw mill for the big stuff.
I learned very early on when playing with tools, anything really, if your into it make some money with it while there. Buy chain saws or other stuff you would never use yourself at price point to flip them fast.
Milling is like money in the bank. Cut a few custom orders of post, beams or slabs and see how fast you buy another saw or five with the money.
You can only run one at time. The average tree service with one crew has about three to five saws. You don't need anymore to produce. You do need back ups if your smart. I've had Echo, Husky and Stihl fleets together all at once. A few Makitas and Macs for fun but the Dolkitas are great work saws to. My point is you will find plenty out there to be had but selling early on is a good thing to do and try more stuff. I bought and sold maybe ten saws before I knew the 048 was my next buy or a 064/660 1122 saw for big oaks and tree stumps. No Husky large saw were available used in my area, still isn't. Mac and Stihl dominated my area when it came to big saws or Homelite. Wasn't much point in hunting for a 281, 288 or 394.
Own some Poulan, Homey and a few others like Mac for collecting. If they run good they sell or trade fast.
Hone your buying skills and on spot diagnosis then you can make some money. The by-product will be finding the cool stuff in your searches.