What's the deal with HF pallet amps? Why so cheap?

Edit: I appreciate all the information and will be staying away from the pallet units I'm looking for something commercial within my budget.

I'm in the market for my first HF amp and am looking for a solid state model. I see several commercial ones available from Ameritron and RM Italy.

But then I see these systems on eBay (with great reviews) and private websites (W6PQL) that are PCBs with all the parts on them and seem to be super small in comparison to the commercial units and with incredibly higher output. Prices are significantly cheaper than commercial stuff.

Yes, this could be a case of "you get what you pay for" but I know that W6PQL's stuff is highly respected in the EME community so I would think his HF stuff is just as good.

I understand for the pallet units, I'd still need a heat sink and proper enclosure and PSU. Still though, that's a lot less than many of the commercial units I'm seeing when comparing the output it would provide.

In the end, I'd rather not deal with tuning a tube based amp. Turn the amp on, use my LDG AT-1000ProII tuner, and make QSOs.

Am I missing something?