ᐅ Converting a Traditional Fireplace

Finally, our search is over and last week we found, financed, and purchased our absolute dream house! The offers we received for a new build were incredibly expensive, so we decided to buy a solid house that is already standing for significantly less. The house is in an almost 100% perfect and renovated condition, with only the fireplace being a bit "old-school." At this point, we would like to install a modern fireplace (a freestanding unit with stainless steel and a large glass front). As you can see in the photo, the floor has just been newly installed. Therefore, the idea is to place the modern fireplace on the existing base and cover it with modern tiles. Does anyone have an idea of what something like this would cost? The only information I’ve gotten so far from a very unfriendly fireplace installer over the phone was: "No idea, anything is possible, between 500 and 12,000 euros,"… yeah, right… At least now I know who will definitely not get the contract…