I think the Ravens would still happily pay Lamar a deal they think is reasonable. Maybe that's still their offer from September, maybe something less, but I'd be very surprised if they are done with him or only willing to go one year on the tag. Their actions (or inactions in regards to a trade or pursuing other QBs) don't really reflect that.
I'm not sure if anyone really knows what the Ravens are thinking at this point. Some of the rumors are that the best offer they extended is now off the table. I can see that.
I think there was a definite shift in their public face last week at the pre draft meeting. I know, it's "Liar's lunch". But the point is at every public function when asked about Lamar it was, "We want Lamar here, we still think we can get a deal done." Or from Harbaugh, "We love Lamar. I'm preparing for him to be our QB for a long time." Last week it was, "We're not going to talk about that today." And nothing from Harbaugh. Who knows what the Ravens are doing behind the scenes?
One thing I have a hard time believing is that the Raven's FO is going to put up with this much longer. They agreed not to negotiate in the press, and Lamar has broken that on twitter. It sounds like they have made every attempt to compensate him adequately, and he keeps refusing. This isn't the way a franchise that is well respected among the league likes to operate. They won't be vindictive, but at some point in time I think they are going to decide Lamar is just not worth the baggage he is building up.