Don't know if states and cities have purchase requirements like the feds but if so I'm pretty failure with them.

Any federal government purchase contracts over $2500 have to be bid upon on the open market for commercial off the shelf equipment. Buy American and minority quotas apply often costing us an extra 30-50% to buy from a smaller minority owned business rather than a nationwide chain.

Contracts can be lowest bid on something simple (like a handgun), best buy, or require a testing and competition (like a new handgun design). Testing is very strictly monitored for fairness often having several panels of subject matter experts independently running subjective and objective testing. Everything is documented and recorded to the n'th degree to protect against protest which sometimes arise with larger ($100K plus) purchases.

There's plenty of ways to get around the $2500 limits - like splitting retirements across several purchases. We'll buy six pistols a quarter for the next eight quarters to replace the weapons slowly say...

Sole source/brand name justifications can be written to justify a purchase. We're going to purchase 24 new pistols to replace 24 old ones from our inventory of 150 total. To retain parts interchangeability, officer and armour training we will demand the same brandname and model number.