Budget single disc player-under $600

The Marantz is pretty well built and sound very decent. I sent one to a friend and he loves it. Now it's mated with a Scott Nixon Chibi DAC and really sings, so it works well as a transport too.

Jolida JD-100 is the player to have in that price range.

Where can it be found, new, at that price?

There is a JD-100 on Audiogon for $560. Tube rolling yields excellent results with this player.
The advantage of buying used equipment on Audiogon is you get more for your money and if you don't like it you can usually sell it for what you paid for it.
Or you can buy one of the inferior CD players you mentioned above.

The Music Hall is better than the Jolida IMHO. I own both. The Jolida does respond well to tube rolling should you decide to go that way. The best tube I found were original NOS CV military type issue 12AX7 Mullards. Before the tube roll it sounded dreadfully sluggish and muddy believe it or not.