I can usally get a model modeled in about 12 hours depending on the detail.
The time consuming part is the uv lay out and texturing.
When i first started it took me a while to get fast at modeling. Just keep with it and the speed will come... As you keep it up you will pick up trick that speed up you technique
I am enough of an artist to draw freely upon my imagination, knowledge is limited, imagination encircles the world. (Albert Einstein)
https://www.artstation.com/kurtb