Your original cost of (124.20) minus tax (102.46) +150% markup (153.69ea)
153.69 per tree x 8 trees for a total of 1229.52
2 trips at 15 mile commute...60 miles...2.00 per mile...$120 Delivery charge. Every place that delivers it will charge around 150 or More for the delivery...so you can charge more in this area.
Rented equipment 255/day + 150%...382.50
Labor (2 laborers $12/hr @ 8 hours) $192
$12 hr per person for a two man team...kinda steep. Good genuine day labor is only $10 But whats the $10 a day difference in the end anyways.
8 bags of Mulch $25
Bagged mulch for this job is the best bet...youll lose your profitablity having to dish around that mulch with shovel and wheel barrow.
Disposal of Soil Clay mixture: $75
I dont know about you but this stuff is reusable if you have a place to keep it...and I wouldnt charge more for this than your local dump would. For me its 5 per cubic yard to get rid of. So just used an imaginary number since yours was so high.
TOTAL: $ 2198.52+Tax. Now you can negotiate if needed because you can knock off as much as 50% or so and still make a profit. This will give you the maximum profitability that your client will accept and not lose a potential lead because you can flex it with a discount. Id say a good 15-20% off should seal the deal and will put it just about where you priced it but your numbers in my opinion look better this way...more accurate...and now negotiable.