Turning a modern condo into a very luxurious one

[Paul Eduardo]

I'm currently looking at buying a 1br+den or 2br condo in SF, 800-1000 sq ft for $1-1.2M. A lot of those are fairly new (> 2005) condos and in an already great state. One idea I had after looking at some interior design videos is to live in it, turn it into an extra luxurious condo and sell it in a few years or rent it out for a premium. Something similar to this but on a smaller sq ft. 

What I don't have a good grasp on is whether modernizing it and turning it very luxurious will translate to the same amount of added value at the end. I'm wondering what some experienced investors think of this idea and if you have any recommendation on where and what piece of data I should gather to better evaluate this plan. 

Thanks!