Buying 1st rehab and need advice

Hello Bigger Pockets peeps,

I have been sitting it out and waiting to do anything for many reasons. I now have found a potential property in Groton, Ma, a nice town with good schools not far from 495. The house is either being sold as land, or as a tear down property. Either way, it needs a new septic, for which their is a design. Anybody know ballpark what it would cost to demolish a house, and put in a 3 bd septic in Groton? The property is 14400 Sq ft or .33 acres. I would like to know what price I should offer. I also know of vacant properties in Acton which would be great to flip or BRRR, but 1 is bank owned.