Here in Florida, especially the east-coast of Florida estimating the cost to repair/replace a defect is the norm, furthermore it is an area of expertise that will allow you to distinguish yourself from your competition.

This is where working a half-century or more directly in construction prior to becoming a home inspector will pay dividends. If you have the expertise to add defect cost estimating and building code specific language comments to your reports you will no doubt be able to command more money for your services which should offset any implied risk, but then again your name would most likely be Jerry Peck or Jeff Hooper.

On the other hand if you have never cracked a codebook, or have never prepared a cost estimate, or are unfamiliar with the construction process, then you will need to spend whatever time and effort is necessary to be able to competently perform these services, the skill unfortunately is not acquired overnight. Furthermore, cost estimating is a skill that becomes easier (read accurate) the more times it is performed.