Its the full game and access to the Arena Commander (Dogfighting & Racing) module, you'd have to pay $5 for other modules though (FPS being the main one, PU could be Alpha too). What it doesnt have is Beta Access, which is a little odd.
Its valued at $60, thats for the AMD sponsored Racing variant, theres also a fighter variant, and a 3rd which seems like a camper (exploration probably) and the racer is likely to be a more expensive variant (presumably the fighter is the base version?).
If you wanted to sell it, you might get $45-50, theres no shortage of ppl selling them, you'll probably be able to 'upgrade' it to one of the other variants, or a 300 series or better at the end of the month, but it'll cost $5+ even to 'downgrade' to a cheaper ship (you pay the difference, with the minimum being $5).
I cant really tell you what to do with it. Its not ideal as a starter IMO, but it'll give you both the finished game (PU online stuff, and SQ42 campaign too) without paying more, but you will miss out on FPS and PU alphas, and the beta too unless you add about $15-20 (£10-12) and you'll be able to earn the rest of the ships in game, or simply take out a loan to buy a nicer starter ship and pay it off in-game.
Also, as mentioned, these next 7 days you can fly all 5 trainer ships, giving you a good idea if the 300/315 is worth a $5-10 upgrade, you can try dogfighting & racing in ships built for that purpose too.