I must defer to your contractor because he should know what the loads above are, what supports them now and what will support the new jamb studs at the new headers and I don't. A double shear connector just uses angled full sized nails that act as connector nails and toe-nails at the same time. I have no way of knowing if that is necessary or appropriate. In designing a structure modification it is necessary to start at the highest point and add up the live and dead loads down to the modified element and then follow the new load path from there to the foundation providing the necessary transfer headers, connections, ties, and braces. As far as I can tell, you have not supplied any of that information.

Benjamin, I would think that an experienced builder could look at it and tell you what needs to be done right off the bat, without going to the expense of hiring an engineer. There's nothing wrong with getting a quote and then deciding to do all or part of the work yourself. The reason I asked if the original builder put up the wall, is that the work looks kind of amateurish to me. Why go to the trouble of building a wall, using that much wood and not finishing it, when a simple beam with support posts would have been much easier to do. What is on the floor over that wall? Maybe a previous owner was trying to correct a problem or trying to put in additional support for something heavy (like a waterbed). If the wall is a true bearing wall, I would think that it's also supporting another bearing wall on top of it. I'm having a bearing wall taken down on my first floor and wanted to move one of the supports for the beam that the builder is putting in. My builder told me that the support had to be there because it would sit over a support in the basement and it's important to transmit the load from above all the way to the ground.

The video concentrates on the walls and not the ceiling, which is unfortunate. It's hard for me to pick out the joists versus the blocking with most covered by the furring strips. But the wall you want to take down, it didn't appear that the top plate ran all the way across the ceiling, from left-to-right. It just went from the left side of the wall to the still-standing doubled up stud with the outlet on it. I'm referring to 1:40 into the video. Based on the location of the room and the framing structure you showed? Tear it down.

Wow. I’m just gonna be straight. I’m very offended. I have no plans to do this myself. This started as just a question about COST. I get that it might be difficult to assess over the internet. I NEVER said I was doing the work myself. I WILL BE hiring a contractor. In fact I mentioned that one is coming on Monday. I was just trying to COST things out. I’m not an idiot. I don’t base decisions on HGTV. WTF? Just to help commenters in the future ... maybe you shouldn’t make assumptions about the OP’s motives, plans, capabilities, thought processes... I got some good info here but I really wasn’t expecting to be insulted in the process. So I’d appreciate it if everyone just dropped it. Pretend you never even read such a stupid question as “how much does this cost” so you can all sleep at night. Oh, and for those of you that think I’m an idiot for wanting to open the wall, please don’t waste my time. I asked about cost. Heck, I just expected someone to say that either there’s a huge cost difference, there’s no cost difference or it’s not possible to know without seeing it in person. I did get that last response and some great info from a few folks. But then I was called an idiot, that I lack a multitude of capabilities, that I base decisions on HGTV, that I have horrible tastes, etc. Wow. Maybe I just don’t know the etiquette. Is it okay to ask questions on Houzz that I don’t know the answer to? Is it okay to not be a professional contractor? Is it okay to not know what I don’t know? Maybe I’ll update this thread after I’ve destroyed my house and I’m living in a shed. Because I’m just that stupid, right?