First of all, welcome to PW........the world of auto addiction (after FB this is what I got addicted to.......lolz).
Bro, price difference is there for a reason. Its not just about the navigation. Aspire has got other things as well, which increase its overall price for example, alloy rims, side mirror indicators, leather interior, under body/engine protective shields etc.
Rumors are that aspire will be discontinued in 1.3 and come in 1.5 (which i personally dont agree with.......both variants 1.3 and 1.5 should come).
If you want all the shaska mashka mentioned above, then go for manual aspire rather then getting these things installed later on in **** and bits