Etes vous intéressé par la location 650 euro le loyer, car j’ai une offre intéressant.

I think I have the gist of it...'Are you interested in renting for 650 euro, because I have an interested offer".

But does that mean I can offer less than 650 or that someone else is interested in renting it so I have to decide if I'll rent it?

Here's what I read:

Are you interested in renting/rentals, 650 euro per rental, because I have an interesting offer.

Think you are supposed to buy/own property to rent out, and make money on it.

You been getting Eurospam??

:D