I am assuming you are talking about 3-5 foot depth in your area. Normal cost would be about $40-100/LF, so about $1600-4200 for the dig, replace, backfill. Add to this any reclamation of landscaping, street, sidewalk, etc. Also add any municipal permit cost, and any cost for the muni or local sewer departmetn to do the actual tie-in to their sewer main - typically $500-1000 more.
So, typical cost for your job, assuming no interferences with trees, power lines, neighbor property, etc would be about $2000 on low end to about $5200 onthe high end - normally a job like this would run about $3-4,000.