Very unlikely that the NAF will buy direct from Bell-Textron because B-T will not be able to pay the obligatory kick-backs to senior NAF officers, due to US anti-corruption laws. If something does go ahead, it will be at a vastly inflated price via an Israeli shell company who will not balk at paying the kickbacks.
Also, who will do the maintenance? I can’t see US contractors queueing up to work in Enugu, Kaduna, Makurdi or wherever they are going to keep them. Most of the SA helicopter maintenance companies who have some tolerance for Nigeria have had their fingers badly burnt by Nigerian Police and AF not paying the bills and confiscating all their tools - so I doubt they will go back in a hurry either.