"Costs" is a plural noun, so it needs to be matched with a plural verb, in this case "are." So yes, you are right about that one!

However, "rising real estates" is incorrect. I personally have not seen "real estates" anywhere and I have a feeling that you're confusing this phrase with "real estate," which is a term that defines land or housing or buildings. "Real estate" is indeed singular, so it would require a singular verb such as "is."

However, "rising real estate" doesn't make sense either, since "real estate" (think of a piece of land or a house) cannot "rise," it just stays there I'd be tempted to believe the correct phrase would be "rising real estate costs," but that's just my feeling about it!

In fact, the only place you'd ever see "real estates" is with a completely different "real" -- the one opposed to "virtual" or "artificial", rather than the one most often associated with property.

If it helps, the "real" in "real estate" actually comes from French "royale" and the notion that all land was ultimately the property of the king; all the other uses of "real" (like "reality" and "realize" and "really") come from a Latin word meaning "thing." It's just coincidence that they look like the same word now; they have totally different histories and origins.