help making a cheap strobe light

I am trying to manufacture strobe lights for some purpose which has to be as cheap as possible.. The cheapest thing which can be done is with 2 bc 547 transistors..

But the problem is I want it to blink twice.. that is 30ms-ON 30ms-OFF 30ms-ON 100ms-OFF that will be O O O O O O O O

so for this I thought using a 555 and a cd4017...

In what other cheapest way can it be done so that I can make little more profit and bring the cost down little more..

If these are high voltage strobes, can they blink that fast? - Scotty

What about using a shift register of some sort (though getting the pulse-train into the register might be a pain) coupled with a astable multivibrator made with a cheap NAND/NOT gates:

Your pulse train is essentially 101000 (repeated) if you can live with approx 33ms clock-rate for timing (that is, your application doesn't need the exact timing you laid out earlier).

any other ways...???

another thing which I thought of is one 555 will flash the LED at 30ms on and 30ms OFF rate that is 01010101

now I will use another 555 to power the previous 555 and this 555 will give its output as 90ms on and 100ms off... so for that 90ms when the primary 555 was high and power the secondary 555 the secondary 555 will flash the LED twice and then the primary 555 will go LOW for 100 ms so no flash...

can only the MM74C14 be used for the same circuit...??