terry's analysis is valid, as far as it goes. there are several other points to consider, however.
first, is your agent showing you all of the mls listings out there, or just his/her own, those of his/her office or of the company. unfortunately, there are some agents who weight their searches to their own or their company's listings. why? obviously, if they sell their own commission, they don't have to split it with another agent. many companies give their agents a bonus if they sell properties in-house. unfortunately, they don't not understand that their primary duty is to the client, not themselves.
many for sale by owner ("fsbo") listings are overpriced or have various issues and defects that you might not be aware of.
however, an alternative that any good agent could propose is that if there is a fsbo listing for which the owner is not willing to pay a commission but which is a good deal, that you could pay the commission. while not popular in los angeles, there are many jurisdictions where buyers pay commissions to agents who represent them. some agents work on a fee basis.
if you don't feel comfortable with the job your agent has been doing and discuss your concerns and alternatives, please do not hesitate to contact me.