そんなものだよ。
It's normal.
That's just what I was going to say.
What of that?
そういうわけさ
I'll tell you [This is] what happened [how it happened].
まあそんなものさ
そういうわけか
そういうことです。
something similar to something previously specified
こういうわけさ
(理由を述べるのなら)―This is how it is―(物語を叙するのなら)―This is how it happened.
Roughly speaking, that is the state of the case.
まあそんなわけさ
This is how it stands.
It is something like this one.
こういうわけであるさま
こうこういうわけで
for such and such reasons
Roughly speaking, that is the state of the case.