Maybe this has already been covered in a previous post or yoyoman's video, but I'll risk repeating it.
If you want to try to make it possible to be ground lowerable, you could use two separate SRT systems, and no lanyard. Then you would always be tied in twice while cutting, and if you used basal anchors for both setups, with separate lowering devices for each system, it might be possible to get you down without climbing. It would be nice if the rescue team also had some kind of mechanical advantage device available to raise the climber a bit, if he got hung up on branches a bit. (Maybe
@SingleJack 's CMI Ropejack invention would do nicely?)
So, this would be DSRT, and like you imply, it might be a bit pricey to set up right initially, but it would be a sweet setup that would provide great work positioning advantages.
As far as a cheap SRT setup is concerned, the Rope Wrench seems like its about the cheapest option out there, just guessing. That plus one knee ascender might be enough. Those are all of my thoughts on this subject, currently.
Tim