Yeah put the 100 odd quid towards a proper cat 1 alarm.
It will cost about 250-350 for the alarm and installation depending on where you go and what alarm you get.
Bit of advice get it installed by a pro who knows what hes doing and you wont have any problems with it then.
Some people say ive got a Clifford etc and its been nothing but trouble, ask them who fitted it and they say joe bloggs from so and so

My clifford concept 300 was fitted to the car about 7 years ago, ive owned the car for 2months and ive not had one single problem with it(fitted by a pro), plus its nice having full closure so if you forget to close the windows they close when you arm it

Do it properly mate, you may be thankful you got it if someone trys to steal it, and you will also get a discount on your insurance if its CAT1