Drew. How do I break this easily. Um no way too. You builders wife wants a new deck and hot tub. And he's trying to cash flow it with your job alone. Ok maybe not but still. Let his boots hit the pavement.
View attachment 440807
That's a 16x36+a 16x15 shed. All numbers are rounded up.
$1,000 for concrete 16x36.
$1,000 for post and second floor joists and sheeting.
$800 for shed materials and truss materials.
$1200 for roof metal and double bubble insulation.
Those are all material only prices. Double them and you get a fair assessment of material and labor. So it should easily fit in your 15k budget. He11 here I could get a 30x40 installed for your budget.
Be sure to add the insulation even in a roof only design. It'll keep it from sweating and dripping on your equipment.
Dirt work was a 12 hour gig. But had to pack dirt 1/4 of a mile with a front end loader. Plus dozer had to dig a little and run back to building to level and pack. I could have had dirt work done in less than 4 hours had I not had to pack it so far. So add $1200 for dirt work. Labor and equipment.
Hope this helps.