The game doesn't really have a "next more expensive ship is an upgrade" mentality. Different ships do different things and a stock ship is completely different to an upgraded ship. I use Haulers all the time for long trips even though I have an anaconda for example. I like to shoot things in a viper or a vulture too
It lets you check out the costs of ships and the power consumption (some ships can't fit all A grade components without sacrificing something else for power).
Always rule number 1 : Don't fly waht you can't afford!!
(meaning make sure you have enough money to pay for atleast one insurance on what ever ship you own)
I would go for cobra next. If you dont have the money, do a couple of rares runs. Everyone should do a few early on to get the hang of long distance travel, it opens up your horizons.