You talk about giving the customer a fair price.....if you loose your ass to this job and you will if you think 2 days. Will the customer give you a fair wage if you you go over you allowed time frame?
Think about this all the plants need to be moved and replanted or cut back for the grid if you plan on using it!
Are you going to dig out the base by hand or with a minni? You renting that? Rock-will you be using a wheele barrow to move it or back the truck down in and use the minni?
You will have more than a 2 hrs of clean up & replant the shrubs and the plants. Re mulch if your doing that too..
DVS is right you should do 5 days or 4 long days to keep it under the 40 hrs..
If you don't like that then do a T/M with mark up not crazy about that but you would be covered. If you would like to give a fair price.. Remember this customer has a job and this is you business and if you fail they don't care or maybe they do but they will not pay for your bills and men just because they care. You need to worry about the company. Not a fair price. You price it to make money. If you don't mind me asking what would your mark up be 05%-10%-15%-20%-25%??