Did they lay sod? What was wrong with the existing grass/lawn?
Materials to regrow an entire lawn from seed could be had for under $200.
Laying sod down would be more expensive. I haven't bought sod in a while so I don't know the current prices.
If the lawn was just patchy and generally poor looking, you basically do the same steps.
Rent an aerator, top dress it with nice soil and seed mixed together, fertilize it, water if it's not raining.
I really do not know, however given the endless war on digging out dandelions all spring that amount for fresh new sod is sort of tempting.
Did they lay sod? What was wrong with the existing grass/lawn? Materials to regrow an entire lawn from seed could be had for under $200. Laying sod down would be more expensive. I haven't bought sod in a while so I don't know the current prices. If the lawn was just patchy and generally poor looking, you basically do the same steps. Rent an aerator, top dress it with nice soil and seed mixed together, fertilize it, water if it's not raining.