Simple access security setup for home

[hhcuriosity@xxxxxxxx]

Hi,

I want to rent an appartment by the week and I need to conceive a
pretty neat setup to let people in.

I want to have a keypad on the exterior door connected to an access
controller that has battery backup.

I will hook up a PC to the controller and feed access codes
automatically to it with a program on the computer (probably a linux
box) through a serial RS-232 interface.

Do anybody know of a cheap setup that could do this. I only found
bigtime solutions for business. Access controllers that handle
holidays, 500 codes and up, etc. I just need to feed it a couple of
codes (5 max). The computer would update the access controller's list
of codes.

I found access controllers that cost 200$ US and keypads that cost 300$
US + electronic strike that cost 300$US.

Are there residential grade components out there?