I have been consuming quite a bit of info over the last few months and think it's time to get the ball rolling! 

Most brokers (myself included) can get the subject properties address and pull comparable properties to get you in the ball park on price but that's only a piece of the puzzle.You'll want to work with someone who can understand what your goals are and what your thesis is for the investment property.

lol @Natalie KolodijShe pretty much hit the nail on the head, everyone can find deals, knowing what to do and how to analyze them properly is a different ball game. 

Frustrated and want to know who dropped the ball? 

Like the golden goose of real estate flipping.

Preferably in the So Cal market, but open to other locals.We just refinanced our small condo in Golden Hill and the rate we received was just awesome!

Afterward, he contacts me to explain his findings put value considerably below mine to justify a low ball offer while offering to send me his comps, which I accepted.

Could anyone help estimate a ball-park number to turn part of an unfinished basement into a 700 square foot apartment (either a large 1-BR or small 2-BR, one bathroom)?  

If I want to put in a low ball offer you need to be 100% supportive in selling the offer to the sellers agent.I would expect you to be bringing me pocket listings.Your function is not to sell me on a product, as my agent you find properties that fit my criteria and you act as a middle man in the negotiations under my direction.

Well, you dropped the ball on this one.