I talked to the TZ company manufacturing the Phoenix bikes.
(NABICO, Nat'l Bicycles Company, has been acquired by METL, one of TZ’s largest businesses, so I actually talked to METL.)
I asked about the price, which is $60, which is pretty good I think. He is open to negotiating further if we buy in bulk. There is an office in Arusha and they cater to farmers, which could be useful if we decide to work with them.
We need to check if these bikes are robust enough and if the Rahi can easily be hooked to it. If that's the case, I feel that selling the package with a Phoenix could help us since the price is so low. Maybe we could sell the whole package in their stores.