Older CA compliant AR or newer CA compliant AR? That will make a difference on the cost to un-neuter it.
Plus the little issue of publicly announcing a plan of buying to purposely flip it and make a profit gets you into a grey area the gooberment is starting to crack down on and will be more strictly enforcing in the future. It's one thing to buy it, not like it, change parts and sell it on. Its another to announce you flipping it for profit. Of course it's no different but why make it easy for them.
By the time you ship it, transfer it and fix it by adding proper furnature and fixing the mag issue I'm not sure that would be a deal anymore.
If a present CA compliant model They got rid of bullet button bastardized mag release in favor of requiring a more permanent mag assembly. It may not be as easy as adding proper parts. Also,
It looks like there is a thread protector there but I dont think they allow that. If they do its welded on.