Believe it or not, there is a thing called Dual Agency in some states where the buyer and seller are fully represented by the same agent. How you can net the seller the highest amount of money and get the buyer the best deal is beyond me, but it's legal! Rediculous, but legal.
Sales price and list price variances are something that you shouldn't pay attention to unless you are listing a home with a realtor whose SP/LP is very close. If it is close that means they either hit the value on the button or they are one heck of a negotiator. Either way they are worth having in your corner.
The SP/LP for an entire area is of little value because you can be averaging what a less knowlegeable agent did in pricing a home too high or low to start with, a home listed by an agent who represented a seller who wanted far too high of a price, etc.
When we represent buyers we can usually hook them by showing them the LP/SP of offers we write and get accepted. This isn't a common practice here, but when you can show a buyer that you are able to get lower offers accepted consistently of course they will want to use you! It's a skill.
One other little point...did anyone else find it rather strange that the seller's agent could so easily subvert the intent of the Colorado law that allows sellers to request that the buyer's agent be a different person (which seems clearly designed to avoid conflicts of interest) - simply by substituting her partner? Even if that is legal, it seems a little dodgy. Of course I didn't have to accept that partner as my agent, but I saw no reason not to at the time. (Since then, however, I have to admit I have become slightly less than comfortable with the situation; and I am not entirely convinced he is representing my interests properly either, though at this point this isn't really much more than a vaguely uneasy feeling on my part.)
Unless you take exact comps (specific address) and compare them to your agents comps we're simply guessing as to why. The comps you are looking at could be completely different than the comps your agent is using.
Values cannot be determined solely based on public records. If they were that reliable banks wouldn't require appraisals and appraisers wouldn't have to be licensed.
Public records is a good resource BUT don't solely rely on it. Having a trustworthy and knowledgeable agent is most important. Ultimately, follow your gut. If you've looked and watched the market you should have a good idea of what is realistic.
As Realtors, we understand your pain, as we live through it daily. You have two issues listed in your question. I will attempt to clarify both. The Listing price is an average for the geographical area Trulia has set for your home. This may not be the best place to get to your specific value with a buyers broker, but rather a Comparative Market Analysis (CMA) performed by your broker is the best way to arrive at a good number to offer. While subjective, this analysis will take into consideration the actual sales of the type of home you are looking to buy. CMAs typically use Solds as the prices to arrive at the value you should offer for a home. If you are looking for a objective 3rd party, get an appraisal on the property. If you are using a lendor, they will order one anyway, but this will get you to the best number for the price quickly. If you are looking for a right or wrong answer, sale price is the right answer, as that is what people are paying for homes in that area, with the caveats above.
As for Seller and Buyer agency, Colorado permits a broker to work with both parties in the contract by acting as a transaction broker. There are certain duties that a broker must perform in these arrangements and should have been given to you in the Definitions of Working Relationships. The arrangement you are in meets those criteria.
All the best in your home buying endeavor.
For example a $210K house sits for three months...so they drop the price $10 grand to 200!
and it sells for 190 so the MLS data says it sold for 95 percent of list price, when its actually like 90% This results in some confusion for many.