The price usually hovers between $160-170. For a one-off purchase, the easiest thing is probably to get it from amazon - the model is the dell P2222H  like the 2 below:

brand new - $170: https://www.amazon.com/Dell-22-Monitor-P2222H-Technology/dp/B096W3MV83/ref=sr_1_1?crid=28VIWVQJJ3YNM&keywords=dell+P2222H&qid=1680113798&sprefix=dell+p2222h%2Caps%2C78&sr=8-1

refurbished - $127: https://www.amazon.com/Dell-22-Monitor-Technology-Renewed/dp/B09CJND9C2/ref=sr_1_3?crid=28VIWVQJJ3YNM&keywords=dell+P2222H&qid=1680113798&sprefix=dell+p2222h%2Caps%2C78&sr=8-3
When I buy them in bulk from Dell, they're $163, so the links above are right on. If you end up deciding to to buy a more than 10, I vote we go through Dell (I can set up the introduction to our rep to establish a school-level account for you), otherwise onsie-twosie on Amazon should work.