depends on how many bedrooms u want cabin to have , depends on the soil, depends on what the system is going to be many different type, a sandmound can be anywhere from 9 grand to 25 grand and more then that , just depends.
That cheap!! Boy, should have spoke with you before I laid down 11,500 for mine. thats was the cheapest too. Got a price as high as 15 K last month.
Yes, the story is how many bedroms,how much sand,etc. The permit alone and the testing will cost you.Lots of variables.
no doubt, this is what i do ,along with general construction,but plumbing and excavating is my main background, and i have done many sand mounds and regular septic and leach beds, $4000 is almost in the ball park for a one tank 3 finger leach bed, sand mounds can and will empty your bank acount quick,my advice would be before you buy land find out what the soil will except and go from there ,see if you want to go the extra expense, good luck.