I bought a Python once. Didn't have enough money to kit it out properly and didn't have enough to fully cover the insurance. Guess what, I lost it. I knew the risk I was taking, so totally my fault. What I did was take a loan to re-buy it with all modules, then sell all those modules and the ship. Then I had enough to buy a Vulture and kit it out properly. I have been flying the Vulture ever since.
I still wanted the Python though and I am still impatient, so I built up my cash to 55 million and went and got one. Then I got back in my Vulture and few off again. When I had another 51 million I went back and bought an A7 power plant. Then back in the Vulture. I have been doing this for a while, gradually adding modules. Once I have it fully kitted and have enough for the insurance I will start flying it, but not before then.
I'm sure almost everyone is tempted in to buying a ship before they have enough credits to run it properly and I'm sure a lot of them loose it. What you should do then is learn the lesson and do it right next time.