Over the years I converted a couple of bikes to flat bars. If you have a nice frame and components I say do it. If the bike is middle of the road then maybe best to get another bike.

On my conversions I had to select the right stem, found some discounted flat bars, installed V-brakes and levers, and trigger shifters. The bike was vintage so I've since converted back to a drop bar for vintage rides.

If you could live with brifter shifting you could always add a cycle cross brake to the drop bar. This allows you to have a brake on the top and also keep the brifter brake and shifter.

Dave