Clay sewer line with root infiltration. Reasonable to have turnkey replace with PVC?

[Account Closed]

So, I got a video sewer line inspection on a turnkey home that I plan to purchase.  It's a 60s build so the sewer line is cast iron and clay.  There's heavy root infiltration at about 100 feet per the video.  

I've never had to deal with root infestation but a quick look through the forums suggest that I should replace the line with PVC otherwise I'll be clearing roots twice a year at $200 each time.  

I figure a 100 foot sewer replacement from home to main drain would be pricey.  Is this a reasonable expectation for the turnkey provider to do?  The pipe is otherwise ok without breaks or corrosion.

Snippet of the report

Interior: ☒ Cast ☐SDR PVC ☐ABS ☐Other _______________________________________

Exterior: ☒Clay ☐Cast ☐SDR PVC ☐Orangeburg ☐ABS ☐Other _____________________________

Transition at: ___34 ft _ _______

Tree Roots at: ___ 95 ft________ ☒Light ☐Medium ☐Heavy ___ ________ ☐L ☐M ☐H

___ 98 ft________ ☐L ☐M ☒H ___ ________ ☐L ☐M ☐H

___100 ft ________ ☐L ☐M ☒H