The article didn't mention corruption but I would not rule it out. Follow the money. Whose pockets are being filled when one transit agency is paying 2x what another one does for the same bus.
I mean, that could just be normal, routine failure to negotiate effectively. If every bus vendor says "call for pricing" and your organisation has "always" paid $940k per bus, when you're told to buy some more buses, you might not even know you can get them for half or a third of that price by getting competing quotes from other vendors.
And if you're an ambitious, hard-nosed type that can really turn the screws on vendors, leaving no stone unturned in your search for savings - would you be working in the purchasing department of a municipal bus company?
Government employees are NOT well-equipped to compete with private sector ones; they don't think like them and they don't act like them. Why? Because the public sector is driven by a completely different model: bottoms-up management, led by the citizenry, not led top-down to maximize shareholder value. In addition, because private sector jobs pay 2x+ what the same level in a public sector organization will pay and thus the candidate pool is simply not at the level that you would expect at a similarly sized private sector organization. Because of this flip-flopped model of operation (bottoms-up vs top-down) Public/Private partnerships are NOT equal arrangements and the private sector companies know exactly how to leverage these differences in their favor.
In this instance, a public sector employee may feel that paying more for a bus will better serve the public good because it /may/ be better engineered, have a longer lifetime, and offer value to the public that's above and beyond what a less expensive model will do. But! Even if the support staff look for multiple quotes from a variety of vendors, all of which may be at the cost level a private sector company may prefer, that public sector staff member may very well be directly overruled by the elected officials; who, for reasons that can only be hypothesized (take your pick: corruption, brand/personal preference, whatever) may prefer the more expensive vendors that were not included in the research and bidding process.
While I have laid out that the public sector is not well-equipped for public/private partnerships and business dealings, there are MANY reasons for this including: candidate pool, different underlying model of operation, and elected official decisioning.
Absolutely not. Cost savings is career suicide in the public sector. The goal is to spend all budget and then beg for more. Regardless of ridership, the ironclad rule is "budget must go up".