Hi there,
the ignition module in deed is very expensive and you want to be sure about it. Start here: Switch on ignition. Take your test-light and test coil terminal 15 (it's marked as such) for 12V- bright test lamp. Good? OK- Let someone crank the car now while you test the other terminal -1 (also marked) for a pulsating test lamp. If you got your pulse on Term. 1, you can be almost certain you've got a good module. If there's no pulse, you need to check the main inputs into the module before knocking it for bad.
Tell me how it went and if necessary I'll give you the detailled procedure on the input test of the module.
All the best,
Dokta