Have just started this project myself and am waiting for most of the parts to arrive.
Total so far ... 5077 parts
... $660 (AU)
So nearly there and still within budget.
Can't wait to start the build, so far have only substituted variant of part (ie. tap with hole in end vs tap with no hole) not the colour.
Just the expensive parts to go ... rigging, radar dish, minifigs etc.