I assume the "little x" at the beginning of the x,XXX means that you see that as lower in the thousands. So assume $5,000 a month. (Assuming high end of low thousands)
To get to $100,000 would take 20 months at a minimum (Assuming low end of 6 figures).
During that time, many a thing could change (Like the source of the revenue, adsense changing all around, etc.).
My personal take: The $XXX,XXX
If this was a realestate hypo, I would view it differently. 20 months is a small time frame.
The risk in internet revenue is much higher, IMHO, and I would therefore cash out should the opportunity present itself.
-Allan