Create an STL File for a Hollow Box (Quickly)? - open to bidding

Hi there again, i hope you are well. Hey i need to make a rectangular, hollow plastic casing, and will start by sketching the model CAD and exporting to STL which i can then convert to g-code and print in 3D. I would like to get your intial estimate and understand your availability. Also I will need to add various features and details once the base box is created. Here is general description: Box needs to be about 6.85" long, 3.75" wide and 0.55" tall. Thickness of walls need to be about 0.1" thick. Open side should be on the 0.55 edge in one version, and on the flat 3.75" side in the other version. There may be a bit of a bevel to the sides, and slightly rounded corners on all edges of the box Can you let me know how quickly you could get this done and what it would cost? I will send you a sketch if it seems like you'll be available and economically feasible. Thanks!