Well, that price is CRAZY! But, Susie-Melissa is one of my favorite all-time calligraphers! I adore her work!
When i was just getting started in calligraphy, I bought a few things from her on eBay. Her eBay name let me know that she was a calligrapher. When I ran into problems, I emailed her in desperation as she was the only calligrapher that I "knew". She was very kind to me & answered all my dumb questions. I'm still terribly grateful for her kindness towards a total newbie!!
And, to the original post: Nibs are like kids. - No two are ever alike! I've had some Brause 66EFs that last for DAYS of meaningful practice/work. Then, I've had Brause 66EFs that wear out after just an hour or so of work. I don't know if it's operator error, a manufacturing defect, the ink, the paper, or what. But, trust me, you'll know when the nib dies! It will become catchy/draggy, it'll be tough to pull on the up strokes, etc. When it begins to misbehave, just throw it out!!
The most durable nib that I have encountered is the Comic G Titanium nib.
http://smile.amazon.com/gp/product/B00LUD4DAY?keywords=comic%20g%20nib&qid=1446387879&ref_=sr_1_2&sr=8-2 The price of that nib is all over the map, with the price right now being particularly high! I don't know why the price is so variable! I check on it about once a week at PIA, John Neal & Amazon & I buy it when the price is lower! It's a very stable nib & it really does seem to be more durable than any other nib that I have tried!
Janis