You need to understand how and why they sounded so good when/where you heard them and then assess how they will work in your room with your listening habits. THere will be differences with teh same setup in any two rooms.
Knowledge is key. The more you understand about why something sounds good or not when you hear it, the better. THen you can apply that knowledge in your specific case to expedite good results. It takes time and lots of listening and asking of questions to get to that point though, so don't rush it and drop a bundle too soon.
The other approach is to set a practical initial budget to take your first best shot, but plan to tweak and change from there as needed over time. BUying/selling used will help provide flexibility to change tweak and adjust as needed without taking a huge financial hit. High end audio can be a money pit, worse than a house for what you might get in return, so do not jump into the deep water too fast.
