If you bid on an item you get an email confirming the bid. You also get an email when the auction ends.Just click on the item and you will find who bought it and for how much
If you click on "completed items" when you search (lower left of page) you can find out the prices achieved by all the similar items which were sold. For example, I have recently bought some cordless phones for a Christmas present, by looking at completed prices I found the phones have sold for between �20 and �40. This not only told me that many people don't do their homework, it also told me that I should be able to get the phones for around �20, which I did. Good luck.