The cost will depend on the amenities.
Last time we had one done was in 2015.
We had minimal amenities - Roads, sidewalks, bus stop, 2 playgrounds, signage, 2 entrance monuments.
The cost was $2,200.
If you have a clubhouse, pool or are a condominium, I would expect a higher price.
Suggest $3K to 5K for budget purposes.
One other suggestion - make sure you know if you want a component study or cash flow study.
Most companies will do a cash flow (aka pooled) study.
We really wanted a component study so had to modify what they gave us.
To learn the difference:
What are Reserve Study Funding Methods and Goals? Cash flow or component funding: Which is best for a reserve study?