A slurry or microsurfacing machine is a large capital purchase that does nothing else, and a chip seal spread needs a distributor truck and a chip spreader running together. Crews need real experience: application rate, aggregate gradation, and emulsion break timing all have to be right, and the failure modes — streaking, raveling, premature loss of aggregate — show up across the whole treated area rather than in one spot.
The practical effect on a bid list is that quotes for these treatments vary more than quotes for paving, and that a low quote from a company without the equipment usually means a subcontractor whose name you have not been told. Ask who is actually applying the material, and ask it before the award rather than on the morning of the job.