Long-range RFID reader

Hi! I’m interested in finding out how I can create an RFID reader that sends data to microcontrollers like RPI. The reading range has to be at least 1m and the cost has to be less than $70 (excluding microcontroller). Some background on the project is that I’m trying to track items that leave a room and would like to place a reader near the door.
Any help would be appreciated! Thank you! :>