Ramps are surprisingly space-consuming, and might involve reconfiguring doorways, gas lines or meters, water, electrical, mucking about with the sidewalk, build

Ramps are surprisingly space-consuming, and might involve reconfiguring doorways, gas lines or meters, water, electrical, mucking about with the sidewalk, building railings and supports, and so on. $100k seems entirely possible in a dense, expensive city. And you might be required to build a masonry ramp. On the other hand, building a compliant wooden ramp to the porch of a woodsy roadhouse might be far less costly.