When is it ever appropriate to put perfect mods on weapons?

For me there are only two times it's ever worth putting perfect mods on a weapon:

1) You found your perfect weapon and you've customised it, might as well put perfect mods on it if you don't plan on switching weapons anytime soon.

2) It's a top end collectors' weapon like a 15>50 req 8 Crystalline or something similar.

For items under 300k, I just don't think you make a profit by putting perfect mods on most weapon. In my opinion it's also much easier to sell clean weapons as well.

Vamp mods being the obvious exception... If you're going to use any weapon with a vamp mod, there's no reason not to get a perfect one seeing as they're on the lower end of the high tier upgrades.

Same goes with +5 armor mod but I was mostly referring to 10/10 sundering, 10% furious, and +30hp.

Well for MY personal weapon i don't care about having perfect mods... i use a drok's sword with a +5 armor and fire dmg (until i find a shocking :O) leave the 30hps and sundering for top of the line items i would never dream of using them myself... i'd rather go for a 29hp for example...

I don't see why +30 hp and +29 hp are like a 35k amount of difference or whatever it is...Will 1 health really help?

no.......

OMG! Perfekt Wingbald Sord!
Gold 15-22 15^50 req 10 10/10 Sunder +30hp!

Make bid of 30 ecto first B/O 60 etco!
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bump!
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bump!
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why no one bid on this my lovely sord?