I recently paid about $15 s.f. for a dry laid square bluestone walk.

wow that is a great price i have got quotes of $18 sf for square ..
Most dry laid I have seen looks like the stones have shifted vertically and without maintenance weeds/grass etc grow between the joints. This look is OK for the backyard, but not sure I want that for the front entrance walkway ... Is this your experince also?

I know this post was many years ago, but I just paid roughly $22/sf in southern CT for a walkway (5 x 7.5 ft) set (wet?) with large square bluestone blocks lined with smaller rectangular bluestone. This was set on a tamped gravel mix, damp portland cement/sand mix over wire mesh, and joined with mortar.

I have large slabs of bluestone in my backyard set in sand/stonedust and they definitely sank down and grass/weeds grew in between in time. I would not recommend this for a front walkway.