I just thought up that, if you didn't have enough credits to buy a ship, why not rent one?
There could be a separate button beside purchase : Rent now!
There also needs to be an hourly rate or daily rate, eg..
Itani Valkyrie:
Cost to purchase: 30 000c (Not actual figures)

Rental Per Hour: 6 000c (One fifth of the buy brice)

Also, there needs to be a replacement fee, say, 4/5 of the purchase price.
This might need to use a mission to work and also License to its availability.
You could add a timer, to the HUD titled:
Next Rent Payment: 45:12:42

You pay (eg. 6 000c) for starting off for an hour.

Any improvements, anything, comments appreciated.
Devs might want to take a look at this..

i just cant think of the situation where anyone does not have the funding to buy a ship. and of course there is the free ship/battery/weapon. even the most expensive ship is VERY VERY INEXPENSIVE.

the average player has over 15 million credits.

Indeed. Ship layouts cost less than 50k at worst, most people have millions. If you somehow don't have enough money, either A) You're new (Go make some! Trading works best) or B) Somehow ignored your depleted bank account (See the answer to A)