I have been working over the last few months an area for a 24x32 pole
barn. I have been tilling with a tractor tiller and scraping with the
tractor bucket.

I am wanting to start on it again. It seems about 7 inches off from the
highest spot to the lowest. The ground is hard now.

What would be the best way to do this? It is hard for me to eyeball. I
am using string and a line level.

I guess what I am asking is should I keep using the tiller or should I
have dirst brought in and try to build it up to level? Expense is a
major concern as I have a new baby at home and we are going to have to
buy another vehicle soon.