When it comes to chainsaws, you can not spend enough.
One of the few products where the more you spend the better the product.
I still have our Stihl Farm Boss bought in 1984 and regularly lend it out to customers whose saws are going to take a long time to repair.
They are amazed and regularly want to buy it then are aghast when I tell them it is still made & available for the same "weeks wages" as it was back in 1984.
But they will not pay the now $ 1400 ( because wages have gone up ) for a new one.
Lots and lots of junk saws out there including the ones from big brands like Stihl & Husqvarna who are forced to sell garbage to get people to come into their shops.
Echo is almost non existent down here as the franchise agent was fairly well pathetic and is now Briggs & Stratton who have their own line of rubbish Chinese chainsaws.
So I only see 20 year old Echos which were top line saws in their day.
As others have mentioned, around 50cc is where you should be looking.
A member of our emergency services gave me a tip decades ago which I have found to be very good.
That is to fit a smaller bar than the standard bar so my Farm boss wears a 16" bar & not the 18" it came standard with.
Then buy 3 chains for that size bar and whenever you refill the fuel tank, swap the chain for a new sharp one & invert the bar.
My saw still has it's original bar.
When the 3 chains have been sharpened to their limit, buy a new sprocket & 3 new chains.
We have nothing other than wood heaters in our home & I have been cutting Aussie hardwoods with it since 1984, around 3 ton a year for us and another 20 or so for pensioners from roadside wind fall.
A good strong saw will have a cutting tooth every second link in the chain.
A cheap underpowered saw will have a cutter every third or fourth link.
As also mentioned, a chain saw is the most dangerous tool the average home owner will ever touch so a short course at one of you community / trade schools before you buy your saw will not be a waste of either time nor money.
It will allow you to decide what type, weight & size of saw will suit you best and how to properly maintain your saw.
A thousand dollars might sound like a lot but over a 50 year life span is a slab of beer a year which is what using your neighbours saw will cost.
A good saw will have an engine that is complete and fitted into the fuel tank.
A cheap saw the fuel tank will be the lower half of the crankcase.