If you truly want to diversify, my suggestion would be that you sample lots of different things and find scents that you truly love wearing. Samples are a relatively inexpensive way to try scents that you might never experience otherwise. Try scents that are on the various lists of top 10, top 100, etc.; try ones that people rave about here on the forum or in the various perfume blogs. Do exactly what you suggest and get a sample of the scent that you smelled in Nordstrom's and wear it a few times to see if you really like it. Don't be afraid to try unisex scents or "women's" scents. The distinctions are just arbitrary conventions. Have fun with it!
I have literally hundreds of samples, small decants, minis, etc., and I have no illusions that I will ever "cover all the bases", whatever that means. The satisfaction is in the journey, not arriving at the perfectly balanced collection.