Each person is different on the learning curve. It took me a good month before becoming "comfortable" with the LA. It is quite different moving the machine and not the fabric. The rates being charged are VERY REASONABLE! Here in Springfield MO the initial class that you are required to take is $100. The rental price is a bit steep, ours are $75.00 for the day.
Depending on if you are doing custom or panto work. Using an easy panto on a queen should take about 4 to 5 hours. Doing custom could be 40 to 60 hours. But it also depends on how fast you can quilt and how fast the machine will go. But I hope this gives you some general information.