What is a large purchase? A large purchase is defined in procurement policy, or it should be. If you have a policy, you should define this threshold. If not, you fall on your state’s policy and their threshold. If they don’t have one, then you use the federal policy.
The federal policy uses the Simplified Acquisition threshold which is normally $250,000. Some funny things happened to it during the spring of 2020.
I looked up Arizona’s policy. Their policy stated that in the event of federal funding their policy guidelines revert to the federal. If you live in Arizona, your threshold is that Simplified Acquisition threshold above.
I looked up Virginia’s policy. They did offer a definition basically $100,000 (§ 2.2-4304. Methods of procurement G.1.)
That’s a lot of words and gibberish.