$200, that is pretty cheap, doors alone run about $40-100 each from suppliers, cheaper if you can talk private sellers down. I can't get beat up doors from my local wrecking yard for under $70 it they are useable for 1/2 doors.
I would say $300 and you supply the doors(or pay for the purchase of them) is a fair deal. There is about $50 of materials i.e., mirrors, sheetmetal, release knobs, vinyl and backing material, screws, steel supports, and consumables(welding, grinding, sanding, bondo, and primer) for a set of doors. I know $125 for labor seems like a lot but there is a lot of labor involved, an easy 4hrs, and when you consider most shops of any kind(welding/body/auto) charge at least $70/hr, $125/a door is a bargain.
The amount of labor involved in factory looking 1/2 doors is why no one makes them for the market place, and is why tube doors are more popular. I have a set of 3rd gen doors I have been planning on making into 1/2 doors, but haven't because I am not sure it is worth my own time, that and it seems a shame to cut up perfectly good doors.
If you are looking for trail doors to save your oem ones the tube doors from
http://www.davezoffroadperformance.com/forum/viewtopic.php?t=444&start=0 are pretty good for only $149.
