I have some HS textbooks that cost us $80-$160 each. Do people really trade such items here?

 I considered selling them back to some of the online sites, but their conditions are ridiculous-- no wear on corners at all, no student names inside the cover, etc.  How are any of those "used" textbooks?  The used books I have bought from those same sites have never been in the shape they describe as their minimum conditions to buy them back.

I have seen some Teacher Manuals here that cost 60-70 each to purchase.  Really it's up to you if you are willing to send the book for a single credit, since PBS policies state that one book = 1 credit.  If you are asking if your books will get requested, the answer is probably yes, if you are asking if anyone posts such books, the answer is also probably yes.  Do they get posted often, probably not, but they do get posted.  :)

I don't think they are posted very often.  I think most people would try to sell them at their local used curriculum sales or at places like the Yahoo group "Used Homeschool Curriculum", HSLDA site or Vegsource.com. 
 

I have gotten some great homeschool items on PBSwap.  I try to always be looking farther out ahead because there is often a long wait but YES good curricula does show up here.

I've received some texts over the years that are upwards of $200 on Amazon.

I typically try to sell my stuff that's of any value over $3 (average cost to send a PBS book) on HomeschoolClassifieds.com first.  If they don't sell in a few months, I post them here.  Most of them have wish lists a mile long.