For your F3HP, AI is fine. You do not need AI-S. AI-S lenses have a small notch in the lens mount that tells cameras with program/shutter priority mode what the minimum aperture of the lens is. Since the F3HP does not have program or shutter priority modes, there is no advantage to having an AI-S lens.

In-fact, you may want to look at non-AI lenses for you F3HP as they often sell for quite a bit less than their AI/AI-S version counterpart. A non-AI lens can be converted to AI for only about $25.

the Nikon "E"(conomy) series lenses were the baby brothers of the Nikkor lenses they had plastic bits but the mount was metal ( a bit like all new nikkors :-) .. They have become legendary.. the 75-150 F3.5 E is quite sought after in the new DX DSLR world. Can functional replace an 80-200 F2.8 with a small compromise in Aperture and manual focus. at 1/10 the price...

$50 is a great deal for a 1.4 50. It will work fine on a F3HP,

I'd get the 50mm 1.4 for 50$ if I wanted a manual focus 50mm prime.

Yes I have done a google search and read that site but I still don't understand and that's why I'm asking here. So the E series was just an special amateur lens from Nikon? Cheaper parts with plastic instead of metal bits?

And the ai-s was just a newer version of the ai with bright orange minimum aperture markings instead of blue? That's it?

So should I buy a $50 dollar 50mm f1.4 ai or get an ai-s or D version instead?

Check the following link. That should answer your question.
http://www.kenrockwell.com/nikon/compatibility-lens.htm

I just bought a Nikon F3HP camera and now I have to buy a lens for it. I found someone selling a 50mm f1.4 ai lens for $50 dollars. I have been told that ai lenses are worthless and I should get a 50mm f1.4D or an ai-s. So I know the ai means Auto Indexing but what is the difference between ai and ai-s and what the heck is a series E Nikkor?

Should I spend $50 on an ai lens or is that too much?