Is 50% discount for launch a good idea?

50% is too high, it makes people question why you’re discounting so much

Software or hardware?

I mean generally speaking it looks quite scammy for a product to offer a 50% discount unless it's quantity limited or extremely time limited. You would be much better off having something more reasonable like 10-20% off if you really wanted to have a launch discount or "early adopter" pricing.

honestly it depends a lot on your launch. 90% of the success of a launch comes from how you structure it. In the end it all comes down to the GTM strategy, pre-launch strategy, positioning, and assets (the video for the launch)