Costs could vary wildly from $10-30/cy, and would be dependent on a number of factors...permitting, disposal site for dredged material, hydraulic vs mechanical, etc. 

(Credit, income & Assets) permits it.  

All contracts, options, or other devices not based upon a substantial consideration, or that are otherwise employed to permit an unlicensed person to sell, lease, or let real estate, the beneficial title to which has not, in good faith, passed to such party for a substantial consideration, are hereby declared void and ineffective in all cases, suits, or proceedings had or taken under this chapter; however, this section shall not apply to irrevocable gifts, to unconditional contracts to purchase, or to options based upon a substantial consideration actually paid and not subject to any agreements to return or right of return reserved.Note it states that contracts or options "employed to permit an unlicensed person to sell, lease, etc" appears to close the loophole.

Take a look at their work and business model and keep plugging away at your job, learn as much as you can about detailing a building, permitting, and construction.  

Being one of them, I am not permitted to count equity in my personal residence as part of my net worth.

My guess is the moderators removed it because it might be considered advertising, and this particular thread's forum does not permit that.

Local zoning, permitting and related issues can bury you in a time-suck.

However, I am confident that there is a reason that the appraiser did not count the extra BR (either not permitted, not proper egress, no closet, etc.). 

Did you Pull a permit for this work ?

Take a look through the threads making requests similar to yours and you’ll immediately notice a trend - the newcomers that overemphasize what they are willing to GIVE (and underemphasize what they expect in return) in their post receive far more responses/support than those who do the opposite.