Skip the Death Star and get plenty of regular Star Wars sets.
The Death Star is awesome, but if comparing amount of figs and useable parts, the spreading of money on different sets would be best.
I have the Death Star myself, but I am a dedicated Star Wars collector (only need the Junkyard, sculptures and some of the minifig collections to be complete) and that's what the DS is. - A collector's item, no more, no less.
Go for quantity and diversity of parts would be my advice.