You need to be in the position where it is the cost of the fuel that actually matters and not the cost of building the rocket in the first place.
(On soft launches) It allows you to test your assumptions and see which ones you got right, and more, importantly, which ones you got wrong. A big hard launch is expensive. Getting even one thing wrong can force you to go out of business.
SpaceX lowered the cost of going into space by 10x.
Historically, the U.S.'s big launchers fly seldom enough that their costs are dominated by annual upkeep of facilities and staff, not by the actual cost of each launch. The expensive part is maintaining the launch capability, not actually conducting launches.
Lighter computers and lighter sensors would let you have more function in a given weight, which is very important if you are launching things into space, and you have to pay by the pound to put things there.
Nowadays you need so much money to be able to launch a new artist, notably in America; you would hardly believe the sums involved.
You can do more science on the ground than you can in space for the same amount of money. But there is some science you can not do on the ground.
Developing expendable rockets is always going to be painful and expensive. Throwing the whole rocket away on each attempt not only costs a lot, it also hampers figuring out just what went wrong because you don't get the rocket back for inspection.
There's no such thing as a free launch.
Alluding to the high cost of the NASA space program and playing off the "free lunch" phrase that is used so often.