I can't get a good number for the total number of transitional fossil species. The lowest number I've read is 200 and the highest number I've read is 2,000. For the total number of fossil species, it usually says 200,000 to 250,00 so that's more consistent on that one. What is the true number for the total number of transitional fossil species?

I don't think there is such a thing as the true number of transitional species, in the same way that we don't know the true number of fossil species, or maybe even the true number of known living species.

First, it is impossible to know the true number of fossil species for the simple reason that we would never know for sure how much of the fossil record is actually missing.

Second, even if we did, the concept of a transitional fossil is quite vague that it could include quite a variety of fossil forms. In some ways, all non-avian theropod dinosaurs are transitional species because they have a combination of features that are shared with more primitive archosaurs (like crocodilians, though they aren't necessarily primitive) and birds. The transition from the primitive archosaur condition to the avian condition is spread across Theropoda, despite popular belief that bird features are only present in maniraptorans (the group including all the feathered relatives of Velociraptor, Troodon, Oviraptor, etc.). Therefore it is extremely difficult to say what is and what isn't a transitional fossil.

Third, it is debatable how many species there are in total. Others have discussed this in much more detail and clarity here at AAB already so I shan't go into it here, but the basic premise is that there are several ways of distinguishing species so it is difficult to know a true number of species.