There is no such thing as the average closing costs.
The costs depend on the size of the mortgage, title company, appraisal company, survey, insurance company, flood or no flood zone, taxes amount...What you can do though, is ask your realtor
to provide you with a preliminary break down of your closing costs on a small house.
70K is a small amount, so it probably will be around 2.5-3K total, more or less, untill we know
more about your transaction.
Also - you might negotiate seller paid costs, if seller is motivated or a bank (foreclosure).
Hope this helps,
Beachfront Realty, Inc.