Greetings,

You don't need a computer to make this work if you have basic
electronics knowledge. You only need a relay / ups / phone. Most
alarms sound a buzzer. Wire the buzzer to activate the relay. If you
don't want to wire anything to the alarms use a $2 mic and a $0.50 741
op-amp. Use a $0.50 555 timer to keep the relay on for a set duration.
If the alarms sound different you might be able to hear which one it
is over the telephone.

I estimate the TOTAL MONTLHY costs (including electricity) at $10
month.
I estimate the TOTAL CAPITAL OUTLAY at $200.

"Chamberlain Communications and Tracfone offer you a year of Prepaid
Wireless with a FREE Phone for under $100 for the whole YEAR! (Less
than $10.00 a month!) Included is nationwide long distance. 30 day
guarantee. Sign up Now - Offer Ends Soon! "
http://www.chamberlaincommunications.../tracfone.html

There are also computers which don't use much power. You might be able
to run the system off of a laptop (monitor off) or even a handheld.
Hope this helps,
William