Hi Arclight, that's an impossible question and you need to find the answer yourself. Because it depends on your history with bikes, if you have any experience tinkering with bikes or cars, what you enjoy doing with your time, what you want to end up with, what resources you have, like tools, workshop, money, and how long you have available for the build. That's probably not a full list of the imponderables.
The good news is anything can be fixed, or even if it can't be fixed it can be replaced. Looks like you have most of the bike there. It's filthy and corroded but I've seen worse that cleaned up to very good or at least serviceable.
I'd probably start by cleaning the bike, there not a lot of muck to wash off so you could go straight to using a rag with kerosene - we call it paraffin in the UK - and see how much wipes off. Good idea to soak all fasteners - frame, engine mounts, engine itself - with penetrating oil. I use '3 in 1', don't know if that's available where you are but any light oil meant for bicycles or garden tools would do. Leave it to soak, then see if things will loosen off.
Further good news - from a quick look at the photos, the fasteners look to be in quite good shape. Do you have any history? How long since the bike was run?
Does the engine turn over? Take the plugs out - might need to leave them soaking in penetrating oil for a few days if they're stuck. Then bung some oil in both cylinders and try turning it with the kick-starter. Obviously, you'll need to remove the carbs, strip and renovate and do a lot of other things before even thinking about starting it up.
And obviously , your gonna need a fuel tank, a new battery, etcetera. But before deciding to spend money, you hopefully have answered some of those questions about what you want. You will never make money out of rebuilding the bike. So if you don't enjoy the cleaning and stripping and renovating, best option is to part it out.
But if you decide to rebuild, restore or chop, good for you, another one saved, I'll watch with interest.