Back in the day (so I am told) you could buy a bundle of 15 Jap Arisakas for $25 and rebuild all you wanted for under a $100 per rifle when a Winchester 94 still cost over $200 so at one point it was something really worth doing. Now days it is something done more often for fun and to show what you can do Vs. an inexpensive game getter.
I did build a rifle for my son but it will be a few more years before he can shoot it still. I have had a number of people offer to buy it off me but I refuse to sell it. To me building something like that is a point of pride long after I am dead and gone that rifle will still be putting 7.62mm holes into things. That is a pretty cool feeling.
If you whole plan is to rebuild and you can why dont you get a striped receiver and work from there. Mauser receivers are still under $50 and there are probably more barrels and parts for them then any other rifle. If you like 7.62x54r and want that caliber get a Mosin barreled receiver and build around that. Dont worry about the politics there will always be a "greatest threat ever and most important election year ever" from the NRA and other Chicken Little types out there. Does that mean that there are not people that want to disarm us all of course not. There are lots of people that want us disarmed even though most of them are armed (
Anti-Gun Senator Shoots Intruder | Field & Stream ). As long as there are people there will be people that want to take something from others.
Dont think about the guns you might get one day for one you dont know what tomorrow holds and I dont know about you but I'd rather lose a few hundred dollars then lose another Grandparent or other family member.
To me guns are like any other hobby some guys have alot of cars some have alot of baseball cards other have firearms if you want to build something build it. Tou can always get a striped AR lower or AK flat and make it into anything you want usually for less then what it costs to buy a new one and you still have built it your self. Or you can go oldschool sporter and build a bolt action off a military surplus action.
You can see the Mosin Nagant that I rebuilt in my photo album if you'd like to see what I did on one of my rebuilds