Talking from experience, I can tell you that simpler cheaper models are not the right way to go.

The reason for that is that they simply don't sell well.

So even though you spend less time making them, your income per hour is decreased because you have less sales.

My advice to you is, don't worry too much about the time you spend on a project. Just concentrate on making a stunning product, no matter how long it takes.

These "wow" models sell really well, and even though they take months to make, in the end, you will see that these models actually increase your hourly wage.

Another thing to keep in mind is that making stunning models will rapidely increase your customer base, and people will come back to look at your future products. You will not get this effect with average  models.

Quality is the way to make money in this business, even if it takes longer.
Shortcuts will only hurt your income and your reputation.

I hope this helps :)