Totally agree, there are multiple sources for a radio with the right features, but you want to buy from one that can fully test and align the radios and provide documentation of that process. You don't want a radio that is out of alignment and won't work properly or, worse, ends up causing problems on the system from being badly off frequency or well off deviation specs.
On the idea of used radios being allowed....I have sold well maintained used radios to some departments myself, recently. Fully upgraded, via legitimate channels, to P25 Phase II standards, they are fully compliant with the department's requirements. And at a cost savings that lets them get four slightly used radios for the price of one new one from their prime vendor. Yes, some departments will allow this. If I make that kind of a deal, the equipment provided is first rate and ships as a complete installation ready kit. All accessories are new or as new, all power cables are new, never used, spliced, or cut. All required brackets are included. What they receive are radio kits that are above criticism. I make the extra effort to deliver the quality that ensures that they'll come back to me should they need more radios.