What about used stuff? Did I miss where you specifically didn't want that?
Example: Kikusui PAB series power supplies are well-regulated, decently made, can be connected in series or parallel, have switched outputs (which was important for me), and use a linear regulated supply. Yes, they are old, but they are also typically fifty bucks. I see a bunch of them on ebay right now.
I have a PAB 32-2A--32 volts, 2 amps. It was dropped and crushed during shipping--really destroyed. There is a switch that controls the power supply to the front panel meter that was physically broken, which I still haven't sorted (the switch itself allows the meter to be externally controlled by a battery--not a practice use case for a bench meter). But after straightening the caved-in front panel so that the switches weren't all jammed up and the circuit boards touching, the voltage output with constant current switchover still works perfectly. That's pretty darn rugged. The unit was not padded properly in the box, and these are deceptively heavy. The box was dropped and the front panel was caved in a good half inch. (The seller accommodated me.) The point is that these are built like bricks and it takes extraordinary bad luck to get one that isn't fully usable.
These have a maximum potential to ground of 250 volts, so seven of these puppies can be stacked in series to produce up to 224 volts without risk to anything inside the units (what you do with the leads is a whole other matter). Or, they can be paralleled to produce up to 14 amps at 32 volts. This is a key advantage of a triple-output supply. They can even be configured for master-slave operation, though doing that is fiddly and is really aimed at a permanent setup.
I have been using until very recently only an old but superb Power Designs 2015A--20 volts at 1.5 amps single output--and these are also available for under a hundred bucks. They were the state of the art in the 70's and still hold up to modern competition superbly. I bought the Kikusui to supplement it.
I also bought, in a moment of weakness, a Chinese switched power supply. The output from it is noisy with sharp pulses from the switcher. I'm told these can be managed with careful grounding setups, but a good linear supply won't impose nearly so much requirement for care. The output of the PD when viewed on the scope is indistinguishable from a shorted scope probe.
The thing these supplies do that regular single-output supplies don't is allow you to limit the current output, so that as you increase voltage into a load, if the set current limit is exceed, it will reduce the voltage as needed to preserve that maximum current output. That's necessary for bench work to avoid blowing stuff up by limiting input current.
And I found an older GW Instek triple-output supply (analog meters) for a little over half your budget. It's on the way, so I hesitate to recommend that without qualification. These are, by all reports, not as beautifully made as a PD, or as cheap as that line of Kikusui, but they have all the features people seem to want with a triple-output supply.
Rick "supplementing the bench with redundancy for convenience" Denney