Ok for residential alarm system, are you properly insures to do this type of work? alarm dealers charge more because they pay big bucks for insurances, also they never install an alarm system without monitoring, and a contract with liability s of liability clauses, with out these your personal liability is way out there.
a snall 3 bedroom ranch may run anywhere from $199 to install a basic system wich is really no real protection, just a panel amd a pir amd a noise maker, not real security, sold bu mass market companies to get the monthly revenue money, then the $2400 monitored system where every opening in the home has a contact, and each opening is monitored for all conditions trouble, opens, shorts, and alarms, also the equipment used is usually better quality.
Alarm work is nothing like electrical work, they are different worlds, and require special skills and experience before entry.