Weather you are waiting for the game to come out before playing it or are playing it right now, it is important to have a ship that you feel at home in. For me, that would be both my Endeavor and my Corsair. For you, on the other hand, and this is really the question that matters, I can't say. The first thing I would put to you is which ship do you really see yourself flying in, or at the very least, spending the majority of your gameplay time in? From what you've said in your above post, you are considering an alternative to the Starfarer. I'd recommend you take a look at the ships listed at this website (all the ships are in one place here) and see which ones you fancy. I'd also ask the while an upgrade isn't a bad idea, you'll have more options open to you if you consider a downgrade as well. You'd have to melt the package down, but you'd get in-store credit as a return, and for the Starfarer Gemeni, you'd have enough store credit from the package to choose from a very large selection of ships. I should add however, that melting down the LTI Package will mean loosing the LTI. Additionally, if the Starfarer Gemeni is part of a game package, you will loose the package upon melting it (if it came with Squadron 42, you will need to purchase it separately from game packages after you do this). It's not a decision to be made lightly, but it's easy enough to get it back. I'm going to assume that you are only interested in the Persistent Universe portion of the game.
If you want to change right now:
Buy a starter package. It's $45 US for a starter ship and access to Persistent Universe. Your options are the Aurora MR and the Mustang Alpha.
Buy the Anvil Ballistia for the LTI
Upgrade the Anvil Ballistia to a ship of your preference.
(Bear in mind, ship selection is limited outside of special events)
If you want to wait:
Wait to melt down until a cheaper LTI option presents itself.
Buy a package during the Anniversary Sale. You'll have a lot of options here.
If the package doesn't contain the ship you want, upgrade it.
(Starter Packages during last years Anniversary Sale were as low as $15 US , this likely will happen again this year)
Now of course I can't promise that a cheaper LTI option will turn up at all, however, a new ships will come out, and you might fall in love with one, in which case, that's a likely LTI option right there. This guide isn't 100%. Things will change in the future. At the end of the day Keeping or Upgrading the Starfarer Gemeni is the safest option. That being said however, you do have options. If you want to know how ships feel, hop into the teamspeak and join us in the 'verse. I think I speak for everyone when I say that we'd be more than happy to let you experience a ship first hand and join us for some fun.
To answer your second question: I simply don't have an answer. Currently they've reduced the overall cost of ships in the Alpha so that they are more obtainable during the course of the patch. I can guarantee that the current prices do not reflect the prices planned for the ships upon release. In terms of making money, Missions, Mining, Combat, and Trading are currently in the game in a limited capacity (some being more done than others). I can only speculate about the state of the Economy upon release.
I hope this helps you make the most informed decision you can. Make sure anything you do is the most fun for you. Weather or not you decide to play today or upon the release, we look forward to seeing you in the 'verse.