For Elite you only need the base game and the Horizons season pass to have the entire game as it is today. Ship paintjobs and other cosmetics have always cost real money but you're better off buying them from the frontier store at the website.

The cosmetics haven't been attainable through gameplay means before but that is about to change, following the next update coming in late august you will earn arx points through just playing the game normally and these can be exchanged for paintjobs and such at the store.

As for gamedeals, I saw Prey was at 80% on steam if you still haven't got it.