I am not involved in the buying and selling of Internet properties, but many companies in "fast-turnover" businesses are evaluated on the basis of sales over somewhere between one and three years of sales (a rule of thumb) - having said that, there are, of course, many many more rules of thumb that various people use.

If you use that as the measuring stick, $150'000 divided by $5'000 per month gives a value of 30 months - 2-1/2 years. It seems to me to be a little in the high side, but that also is the starting point for the negotiations. On the down side, you do not know (or at least I don't) whether Jami has a large personal following, in which case, the sales can drop significantly when she is no longer personally involved with the operation.

Good luck Jami, both on the sale and your future activities!