Check out the SenseCap solar node. It's way under $200 and professionally built.

https://www.seeedstudio.com/SenseCAP-Solar-Node-P1-Pro-for-Meshtastic-LoRa-p-6412.html

Probably the best configuration for it is as a regular client client_base role since that will relay like a repeater but without forcing other clients in the mesh to use it (which would be problematic unless you're in a super ideal position).

Edited b/c I forgot about client_base. See the reply to this one about that role.

Want to set up a powerful

The solar node won't be more powerful in the "radiated transmission" sense, but will have greater reach because it's outside. And height is might as meshfolk say.

solar rooftop node/repeater/router

As others have correctly advised, nrf52-based nodes are power-sippers. This makes them a good fit for solar nodes.

I see some folks on eBay selling $200 home built solar stations. Could anyone recommend any good options for this kind of thing?

I bought one of these from PeakMesh, an etsy/ebay seller. <$100 . Very happy with design, build, performance, and the entire buying experience. I usually prefer to DIY everything but this node checked all my boxes at a sane price.

I've run it as a Meshtastic client base and now as Meshcore repeater after bigger dogs on my local mesh went that direction.

trigger warning - the remainder of the post contains references to reddit which may cause apoplexy in some viewers. :-)

The seller is active on reddit as M-growingdesign. He made a post about this particular design in /r/meshtastic. It was basically marketing but there's a good bit of discussion in the thread, including how he made design decisions.

I just want to buy something and screw it up

I see we are brothers from different mothers :-P

I, and several others, have been very happy with the "Ultimate Solar Radio Node" that is available from PeakMesh on Etsy. It runs around $130 and it works perfectly. Ours has now been up for most of a year and has not required any attention at all.

There are also plenty of options for building your own. I found that doing it myself the way I wanted to wasn't going to save me all that much money. Being lazy, I bought one off-the-shelf.

Im not an expert by any means, but you can get setup with a rooftop node pretty cheaply. You’ll want a NRF-based device for power efficiency so like a RAK WisBlock 4631, then a decent antenna, Rokland has some good options for higher gain fiberglass but your local mesh or HAM club can probably help here since there is a lot of garbage antennas out there. You will probably want an MPPT charge controller as well since the on board one is pretty crap, our local mesh often recommends an option from Aliexpress that’s less than $5. You can build your own node for less than $200 though for sure. If you want a ready to go option, I’ve heard good things about the SeeedStudio SenseCAP P1 and it’s less than $100.

All that said, be sure to coordinate the role with your local mesh. A poorly placed router can cause a ton of problems. Almost all rooftop nodes should be client or client_base.

No experience either, but searching around a few days back just for fun came across the Heltec MeshTower which seems to be what you're asking (but is currently sold-out).