Is 40$ too much to ask for a simple one landing page website?

Tell this to the client I recently met. He's offering 12$

Depends where you sell your service?
In for example India this would be probably ok but if you would sell it in Germany it would be to little.
It all depends on your hourly rate and skill.

Your hourly rate is calculated like this.
Cost of doing business + contingency + your desired Salary + your desired profit margin = your rate

@penis fuck off mate, i need proper food and rent. so fuck off and get yourself fucked.

Depends on how simple it is

If I could finish it in fifteen to twenty minutes, $40 sounds about right.

@retard then build them $12 worth of WordPress or Wix. Would literally take you like an hour or so, and then let them bite the annually fee if they don't like the "Wix" banner on their site.