actually without competing interests, a weapons procurement could be very simple thing to do.
Competition ie. a tender would make it a lot faster.
Bargaining ie. visiting each electronics supplier one by one and trying to break price down keeps it getting longer and not an easier to way get lower prices, instead it can even increase the prices. Companies tend to like loyal customers to safely deliver technology and maintenance capabilities so that it can ease their burden: not easy to schedule, dispatch expats and spare parts thousand miles away and manage stocks for each country they have worked with.
I happened to see some electronics suppliers prefer to bid lower when they sense an "easiness" in procurement and contracts,especially to a loyal customer.
I also happened to see that same system was being sold twice as expensive just because the supplier has known how problematic that country was and caused procurement to be tedious and prone to be failed.
I have been telling for years, a country like Indonesia with a great appetite of procurements to happen in next decade should choose permanent suppliers for certain parts and keep it that way and move on to local systems when local industry has matured.
It doesn't take forever though...
Especially when the contractor has already built similar ships and worked with numerous suppliers.