Having both the 3008 and 698, I agree with other posters. The 698 is worth the few extra $. How much is you time worth fixing a too-cheap pen?
My time isn't worth anything unless someone (which could be myself, or anyone else) is prepared to put a price on it that I can bank.
I'm happy to do some preventative maintenance on something known to be at risk of breaking, failing, deteriorating, whatever. I just ordered a lot of sixty M4 x 0.6mm screws (because the M4 x 0.4mm screws I bought on eBay proved not to work for this purpose) for US$2.50 delivered; that took a few minutes. When they finally arrive, it'll take another few minutes to collect from the post office on the street corner, and then several minutes each to replace the screw on every one of my soon-to-number-26 Wing Sung 3008 pens. How much would that time be 'worth' to me? Well, less than the satisfaction I get from knowingly mitigating the risk on 26 cheap pens to end up with two dozen well-performing pens.
On the other hand, if my A$4 Wing Sung 3008 breaks or gets corroded beyond easy repair, then I'll just throw it out and replace it with a new one; it's not 'worth' fixing or keeping. It's not as if I want to avoid throwing out plastic items in my trash.
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