The boat is the only one that may be brushless as the description says it uses a LiPo battery that was included when purchased. From your new pics, most of what I see is dirt.
Ultimately "worth" is what you are willing to give and they are willing to take. It may not be a"too good to pass up"...
Wow, some of you guys like to steal. The Mutant edition of the Stampede is $400+ new. If the Monster short course truck is a slash it's also extra$$ new.
Used doesn't necessarily mean abused junk. If buying used you need to KNOW what to look for and check them over. Low-balling when you don't...