A touch of class is something that means different things to different people. The impression that it brings up in most minds is probably the idea that a lot of money has been spent. Expensive champagne. A top-of-the-line car. A dress that looks like it was made bespoke by a name designer. All of these are things that people associate with class. For better or worse, the word class has come to be synonymous with price.
Let's be honest about this, there is good reason that this has come to pass. Class has come to be associated with cost, because the theory goes that anyone can spend a little money, but only the few can spend a lot. But there is a flip side to this. We've all seen extremely rich people who spend a lot of money on something just because it cost a lot. How many of us think that, for example, a gold-painted Rolls Royce oozes class?
When planning an event, this is something that needs to be borne in mind as well. If you have an unlimited budget, it should be easy to plan the perfect event. But there are some events that cost a lot of money to put on and give of all the understated glamor of someone setting fire to a large pile of cash. A lot of money and glitz does not immediately denote class. Maybe some people think the Trump Tower is a wonder of architecture, but a lot more do not.