I'd be careful taking pricing advice from other contractors because everyone has different overhead, different crews, and different business models.
Instead of asking, "What should I charge?", I'd ask, "What does it cost me to stay in business?"
Figure out your labor, materials, overhead, insurance, vehicle costs, taxes, and the profit you want to make. That's your minimum. Then compare that to what the market is willing to pay.
If some people say you're too expensive and others say you're too cheap, then you're probably somewhere in the ballpark. Not every estimate will turn into a signed contract, but you'll see where the market is at and what clients to avoid.
As a general contractor, we sub painting and we've seen prices all over the map. Some include protecting the floors, doing the latex caulking, filling nail holes etc. Some ask for that all to be done before they come in. If you include those things, add you might want to add them as a separate bundle so that you have a built in bargaining chip. "Look, we could hit your number if it's all prepped for me and I just need to paint".
One thing I'd also recommend is calling a few painting companies in your area as a homeowner and seeing how they quote jobs. You'll learn a lot about what they include, how they present themselves, and how they justify their pricing.
Do you aim mostly for homeowners? If so, try to aim for general contractors. They have a steady pipeline of work. If you get in with a few GCs, you'll be less exposed to the cheap homeowners.