This site is by far, one of the best sites for info on surface bonded concrete block construction. The author has actually built some buildings, and has quite a few tips and tricks to make the process better.
For example, he suggests leaving gaps between blocks at corners, to prevent irregular wall edges and openings.
Other reference works have the owner / builder use metal shims, and endlessly fuss with filling gaps. He just uses mortar to fill in the gaps before applying surface bond.
One of the biggest problems with surface bonding is that it has been shunned by the traditional building industry, and few block manufacturers make full dimension blocks. So you have to use regular CMUs that assume a 3/8" mortar joint. Plus the corner blocks have one side that does not have a joint - so the dimension is slightly different. It's enough to throw off careful measurements and modularity.
Concrete block construction is fairly inexpensive - if you prepare carefully.
A 32 x 32 x 8 structure (1024 sf) would use roughly 1200 blocks. (less block because of openings for doors and windows)
Depending on cost of surface bond cement and the blocks, you can certainly get your costs below $10/sf that the masonry industry suggests for standard mortared walls.