went through this earlier this year so figured I’d share since I couldn’t find a single honest comparison when I was looking.
we had water coming in at the base of the foundation wall on the north side. not a flood, just a damp streak after heavy rain that was slowly getting worse. five quotes, spread from $4,200 to $22,800 for what I initially thought was the same job. it was not the same job.
the $4,200 quote was interior drain tile only - basically a channel cut into the basement floor along that wall, a sump pump, and call it done. works for managing water after it gets in but does nothing about the actual entry point. also means your sump runs forever and the foundation is still getting wet.
the $22,800 was full exterior excavation down to the footing, new drainage board, new weeping tile, waterproofing membrane on the exterior face of the wall. proper fix but major disruption and that price included redoing the landscaping on that side of the house.
ended up going with The Local Builders (thelocalbuilders.ca) at $11,400 for a hybrid: crack injection on two visible cracks from inside, interior perimeter drain on that one wall only, new sump with battery backup, and drainage improvements to redirect the downspout that was running toward the house. their guy spent an hour with a moisture meter mapping the wall before quoting which none of the others did.
six months and two major rainstorms later, nothing. I don’t know if I got the optimal solution but I got an honest assessment and the price felt fair for what they actually did. biggest lesson: the quote price tells you nothing without knowing what work it covers.