Yes, being able to rebuy your ship (not lose your progress) is probably the most important thing to avoid frustration. This becomes especially true if and when you start to engineer your ships which can take time, gathering the materials and so on.
Depending on what types of ships you fly this really isn't too onerous though. I fly only small and medium ships, and I think I only have a few that cost more than a million to rebuy. And making a million credits isn't really that challenging.
I actually logged in last night as I felt like playing something, and flying spaceships seemed to be the favorite. Took a mission to destroy a pirate lord... Don't drink and fly! I got sloppy and my very slow and blurred reactions caused me to lose my ship to the naughty pirate! So, I re-bought my ship and went after him again and this time tried a little harder in in a few minutes he was gone. Decided to take one more mission after that which went off without any silliness.
Cost of rebuy, around 500,000 credits. Mission rewards 6 million and some biotech conductors, bounties another million so I still came out ahead. But yes, early on be sure you have those credits in reserve.