Car Alarms: remote control, subaru legacy outback, subaru legacy

I have a Subaru Legacy has the original alarm...and I am having trouble with goes off suddenly but the remote is in bad shape ..I need the remote but is to expensive at the agency.  Is there some other brand compatible with it  but less expensive??
thank you!!

Please be more descriptive if possible.


I need to determine whether it's a factory alarm
issue or, if it's an aftermarket system you are
dealing with.

Ok let's clear up the terminology glitch here.

1. FACTORY/OEM alarm = Part of the original schematics
and plans from the manufacturer.
(horn honk, head lights flash, Starter may crank and
die, no spark)

2. DEALER INSTALLED alarm = Just that. Once the vehicle
is brought to a dealer, the dealer sub contracts the after market
security out.
(horn might honk, siren and parking lights flash, starter kill relay,
no start, no crank, just dead.)

3. AFTER MARKET alarm: Same as #2 but Customer IS AWARE that
the system was put in at the dealership, but may not
be informed of the brand name, or even what it's
total capabilities are.
(siren & parking lights flash, starter kill)

Which one applies to yours?