even easier approach - the software is probably already installed on your system..
run netmeeting (if you don't have tyhe software, you can get it free at microsoft.com)
you can set up the webcam (yes the cheapo webcam will be fine) up on the front desk pc to automatically begin sending video to the office pc, whenever the office pc "calls" the frontdesk pc. you (office pc) in turn do not even need a webcam..just view the front desk webcam..add a microphone if you want, and you can eavesdrop as well. you don't need to buy anything, as long as the two computers are networked, and you have one webcam.