I like the hammock approach, $300 is on the edge unless you use a CCF pad. I would want a good durable hammock for that many nights. You could use many hammocks with integrated bug screens like a bivy with a CCF pad inside a shelter.
That aside, with the use of shelters on the AT, I would look at a tarp and bivy approach. The bivy will keep the bugs at bay and allow cowboy camping in good weather, with the tarp filling in the gaps. One of the models with a waterproof floor, breathable top fabric and insect screen is what I'm thinking of.
If he wants low weight and cost, I would get over the guy line thing. All the so-called free-standing double walled tents use a ton of stakes and breakable gee gaws to pull it off.
Adding another simple carbon fiber pole is hardly a stumbling block for weight or cost.
I use a Gatewood and it works well for me. Like any enclosed single wall shelter, it will get some condensation. It may be too short for taller guy. There are plenty of shaped tarp shelters that don't double as rain gear. I would point him to SMD or Henry Shires/Tarptents
If you guys are going together, a couple bivies and Borahgami would make a good 2 person setup. If you both used ponchos with the bivies, you could camp solo or together with the Borahgami.
There are plenty of good mids out there. Sounds like a pole extension and bug protection lead there. As above, if it is single wall, it will get some condensation.