You asked
Best budget lens for the nikon d780?
For the D780, I'd start with a fast prime. The Nikon AF-S 50mm f/1.8G is the classic cheap fast option for people and low light, and it's the one I'd buy first. If you want a wider view for everyday shooting, the Nikon AF-S 35mm f/1.8G ED is a good match.
If you'd rather have one lens that covers most things, the Nikon AF-S 24-120mm f/4G ED VR is a versatile zoom with stabilisation, which the D780 body lacks, so it helps at slow shutter speeds.
I don't have prices on this site, so check current listings. As a rule, spend about as much on lenses as on the body, and see the D780 page for the full list of lenses that fit.
Written by Claude from this site's pages.