I've been lurking on this thread for a while, and following this excellent discussion. Here's a few thoughts from my experience --
(I should say that I have owned 5 mills over about 30 years, and only bought 1 of them new, and have 'consulted' on the purchase of about 5 more.
Industrial machines are built pretty tough, and they are used hard. This makes it pretty easy to spot a 'dud', especially if it is powered and you can run it. (there are a few good 'mill buying guides' on youtube and the 'net)
You live in a place where deals come up often, and even though we say be ready with cash - you can afford to be picky until you get one that your are comfortable with. Then spend the money and be prepared to take it what ever it is.
@Susquatch has super relevant experience here - when I saw the condition of the Hartford I could see from the photos that it was a very good mill at an excellent price. For a first mill, be prepared to spend a little *more* so you don't spend your early year(s) repairing a boat anchor.
Bargain mills are almost always that - a bargain that someone ELSE should be buying.
Lastly, don't worry too much about the parts thing - don't buy that mill that the parts guy wants to unload BTW - Most mills in good shape, used properly, will outlast you and your hobby. If you were going to do 4 hours of milling 5 days a week, you need to buy new from the start, a brand name that has a parts pipeline.
If youn are a hobby guy like me, 4 - 5 hours a month is more like it.