They need to go to a freemium route more or less immediately. Here's what I'd do, or what I would've done:
1. Lower expectations from the outset by pricing this as an indie game with optional, microtransactional upgrades. This literally solves every problem.
2. Sell it for $20 or $25 and then make necessary inventory upgrades for something like $1-$2 each. Cap it however you deem fair. Immediately they're right back around the $60 per buyer mark while also getting more generous reviews.
3. This desperately needs to be a cooperative MMO with alliances and guilds and different base ships -- science vessels, traders, hunters, battleships. The ability to stake out, claim, protect, and fight for additional territory. Building your own space stations. In-game community building.
4. With a lower price point, you get more generous reviews while also lowering expectations. With microtransactions, you solve the game's biggest broken mechanic with limited inventory. And then building an MMO on top of this with 4 different play styles -- zoological discovery, money making, combat (say hunting traders and popping them for their spoils, protecting your traders, and hunting other hunters), and alliance conquests -- you make this game infinitely more enjoyable with a lot of ways to approach your own personal style.
5. A quintillion is too many to make all of the above fun. Lower it down to say, 1 million planets. 1 galaxy. Resets every 3 months. Go.