for the $300 price range then have a look at the corexy machines.
Much better engineered, faster, silent and really good quality out of the box.
My twotrees sapphire pro2 has fast become the go to machine both for speed and quality in my workshop.
Retals at $300.
No hardware upgrades required or should ever be needed.

I printed a bracket to convert mine to direct drive and an elevated filament holder.
And that's it.
I do have an I3 I also have a couple of deltas and a replicator pro.
So I've pretty much got all the current fdm mechanical styles covered.

The corexy has been a complete revelation. You've got the speed of a delta with the rock solid engineering of a replicator pro and the simplicity of build of an I3.
I think the only reason more people aren't making these is that they do require avery solid and stable frame.
The sapphire pro is a beast !
The top plate is 6mm aluminium plate with quality linear rails attached.
The base is made from 2.25 mm steel. It's a heavy beast and the frame size is large for the build volume.
But that said - if i ever have to buy another machine or set up a print farm - it would be corexy all the way. And the sapphire pro 2 is a great example at an amazing price.

I mean i didn't pay $300 I got mine second hand for a lot less.
But it's one of the few printers around that are a really good buy.