XL - Basic work truck. Not much in the way of "creature comfort". But most of the stuff the XL's are missing can pretty easily be added on to make it an XLT
XLT - XL plus a few extra goodies such as power doors, windows, cruise control, front grille is shiny instead of black, and a few other odds and ends.
Lariat - XLT plus leather seats, power seats, power mirrors, and a few other odds and ends.
King Ranch - The big daddy of super duty's. Main aspect would be the leather on the inside. It's extremely high quality saddle leather. IMO worth every penny. You won't have to worry about it though because 7.3's weren't available in King Ranch models.
Harley Davidson - really expensive, really nice leather, really nice truck.....king ranch is better
For most guys on here an XLT is all you'll need. Has anything an ordinary person would want/need to get from point A, to point B, and back to point A in a day. AC, cruise control, six way movable seats, adjustable lumbar, fold down center console/6th seat up front, and most importantly.....cheap
. My XLT more than suits my needs. Only other thing i would have asked for would be power folding mirrors. Would make parking a bit easier.
As far as price is concerned depending on a range of things (mainly what it used to be used for and miles) a 99-03 7.3 will cost somewhere between $5k to $12k. Then again that's average. Mine was $12,500 a year ago with 94k miles. I think i payed a little too much for what i got but hey....I'm happy with it now and that's what matters. What options are you looking for? DRW? Crew cab/super cab/single cab? Long bed/short bed? etc.....