Sewer connection costs can vary greatly based on a number of things. I would check with the local building / water sewer dept for a list of approved contractors who will be able to provide you a acurate cost.
Some factors to consider 1. how far is the sewer main? 2. Is there ledge?
Yes it can vary. I recently was looking at an Ashland property with a client and was quoted between 6000 and 12000 by the broker to hook up to town sewer. As stated above, there are a lot of variables so you need a professional to quote. Most towns have a list of approved contractors to quote and do the work necessary. I hope this helps.