I want to sell my website www.surplusbearing.net alongwith all material
and two more domains www.surplusbearing.com and surplusbearings.net
Will any body tell me how much amount I can expect and where to sell?

My site is for BEARING industry and trade and I am running this site free
for all.

You could try to sell it at www.sedo.co.uk
but do not expect to have it happen within a week or so. 
at least better than selling at ebay where the audience is 
often too small so results are often disappointing,
that's what I found at least when starting with 1$

www.forex-traders.info

Well if it is just a virtual business (You said it's just a directory
right?) Then there are tons of administrators who would be willing to
buy your site if you posted it in the classified section of
www.webhostingtalk.com.  I have seen websites sell there from $1,000
to past $25,000.