How does someone who isn't an electrician start getting an idea of what equipment they need and how much it would cost?
I don't want to run my cabin off a series of Jackery panels and batteries but that's what I'll do if I have to.
A) your current usage (and cost). There are big amounts of money in play, so ideally uou want a solution best sized to your needs. 1 person living alone consumes a lot less than say a family of 4.
B) where you live. Not just big picture (latitude, climate) but also local details like shade coverage (mountains, trees), roof pitch angle and roof direction.
C) your goals - do you just want to reduce your bill, go off-grid, deal either regular power outages, generate excess back yo the grid, and so on.
D) install costs. Some buildings are easier than others. Some roofs are space-constrained. Etc.
While "ball park" pricing is reasonably easy to determine, spec'ing the right system for you is going to take all the above into account.
Ultimately your costs area
A) number and capacity of panels
B) size of inverter
C) capacity of battery
D) installation of panels, and electrics.
There's lots of info on the Web, but start with some basics. What are your goals? What is your current electricity consumption? Peak, daytime, nighttime? Can you use grid for backup?
I've done a fair amount of research for my own system, so I'm happy to expand if you want to give more detail.
All the major players are playing fast and loose trying to milk the subsidies. Better to at least learn enough about how to do it yourself so that you can verify that you're not getting screwed even if you hire it out.
You could setup a 12V or 24V system, which is relatively safe to work on. But that won't run your fridge, etc.
I had no trouble finding suitable panels, inverters, controllers, etc on eBay.