Oh no, don't get me wrong. I realize even with missiles that are currently fielded, the obstacles for us to be able to reach the capability to build one ourselves are gigantic. And it's not about 'skipping classes' either.
It will be a long way, I know, but then I start asking whether it will be worth it if we still only be able to produce 'basic missiles' while the threats already fielded their more advanced ones? And, God forbid, what will it be if we're already in armed and major conflict by then?
And yes, about R&D, unfortunately this is where we're still lacking the most.
And what happens if a major breaks out and even for those simple missiles Indonesia relies on foreign logistics? If foreigners can possibly provide those simpler systems now, they can also provide the advanced and cutting edge systems when a major war breaks out. At least in that time, there will be no reliance to foreigners for the simpler systems
-Better than nothing, definitely,
-Will provide a base knowledge for future or customized weapons, definitely,
-Will still have a use in near and mid future with basic upgrades, definitely,
-Can benefit some other possible munitions to be used from Drones, definitely,
It looks really reasonable to start from now aiming a simple rather common step and gradually gearing up as technology and capabilities advances.
For example if a high subsonic AShM is made (or any of the major items marked with bold), it will also benefit
coastal defense missiles,
LACM,
ALCM, loitering munitions, light low-cost cruise missiles, smart missiles, guidance kits.
As technology advances, replace the seeker, improve the seeker (dual mode seekers, LPI seeker, home on jamming, home on radar), add uplink and target update (man in the loop, network up-link, swarming), image processing (way point guidance, target identification and specialized attack plans for each target), make it jam-resistant and finally use common systems and introduce a supersonic version once sufficient knowledge has built up.