Stripping – $54–$151/100 sq. ft.. “The principle of paint strippers is penetration of the paint film by the molecules of the active ingredient, causing its swelling; this volume increase causes internal strains, which, together with the weakening of the layer's adhesion to the underlying surface, leads to separation of the layer of the paint from the substrate.”— Wikipedia. All the stripper will do is soften the paint. You’ll still have to scrub or scrape it off.
Plan the schedule. Get a grip on the time it will take to bring the project to fruition. Plan for time to move furniture, wall prep, cut in, the painting itself, eating and breaks, and don't forget cleanup and bringing furniture back in. As you plan, err on the side of prudence. Unforeseen events will slow you down, so allow time for these. Remember, this is a multi-day project. Don't try to fit too much into a day. If you move faster than planned, great!
Most of a projects price is the cost of labor at $25 to $75 per hour. However, most contractors bid out based on the entire project which includes all work hours. Hourly rates are only useful if your pro asks to do the job as “time and materials.” However, be wary of this pricing structure, it usually shows the contractor is uncertain how long the project will take.