Well why then when you ask for a part in the want add. Shouldn't you add a price you would like to pay. Unless you are reasonable with your offer for the part. you won't be bothered by someone who doesn't want to help you.
It's a don't waste peoples time with want ads if you are fishing for a smoking deal. Especially when lots of times those same want ad parts end up for sale at a MUCH higher price.
I've answered some want ads with a decent price and that was told that's too much. It was much less than a similar item listed for sale section. Go figure.