Royal Tiger kits are becoming less and less full of original vintage colt parts. Other places strip out the the third pin and auto trip(or substitute the trigger and sear assembly out entirely) when selling the kits. Not that the parts will do you any good for a new build but they do have a market value....
I would look closely at what is still in the kit.
RT no longer supplies Colt Bolts and replaces them with generic no names, yet charges the same price. You'll get all the parts though.
I order two kits and have a thread a farther down with summary pictures
http://www.ar15.com/forums/t_3_123/680626_My_2_Royal_Tiger_Important__kits_Photos__also_restarting_thread_since_others_were_archived_.html which has links to the two previous threads on the RTI kits. I was hoping for feed back and identification on what Royal Tiger Imports sent for parts based on their reputation. I'm very new at the Retro Game. I was just happy finally having the A1 grips and Triangular hand guards set up. Although the hand guards finish I received feels very weird compared to all the triangular hand guards I have ever felt. If you want the full detailed photos of all the kit parts let me know and I post the full gallery link . The kit quality is declining from what I can tell. The kits I show were from memorial day sales, the RTI site photo has not been updated to show the current parts in the kits. They did post a notice about the bolt substitution which raised a red flag.
At this point the m16A1 kits have been depleted and you'll pay for a good full kit(no broken stock, minus trapdoor/butt plate which NOS is cheap and readily available still, and no missing/cracked teeth on hand guards) or get the bottom of the lot likely. So look closely. Paying more for individual listed kit might be your best option and/or using the more expensive higher end sources.
Also watch for cracked and split metal on the upper receivers. There is a repair thread on here showing examples and it is impressive gunsmithing/welding work. The cost if you have to hirer someone to weld it for you might be more than buying another replacement upper receiver.