Boy they sure do have a ton of kits. Many not seen by our vendors. I ordered one kit to see how things play out and not being in a hurry because I can not get in shop till sometime in Dec I took the cheap way for shipping. If you tried their new Majestic kit I would be interested in your thoughts. I wanted to try that one too but did not. I looked back on a bunch of older threads here because this topic gets brought up many times as far as quality. It was also brought up that their kits are clones of PSI and other Tawain kits. Weather that is true or not is still out there. The Panache, sierra, kits and many more are spot on look-a-likes. Shipping can be a killer but as you did if you work the numbers the increase is not much per kit.
I have not tried their Majestic kits.
One thing I've noticed on their fountain pen and rollerball kits that I don't like is some, not all, have fine threads where the cap screws on to the body of the pen. You have to rotate the cap 4 or 5 full rotations to get it tight. They do have some others that have coarse threads and take maybe 2 rotations. From the picture it looks like the Majestic has a more coarse thread.
Another thing I've noticed is it seems their molds (or however they are made) are not as detailed and "refined" as those from Penn State and Dayacom. For example they have a golf pen that could be a good seller but the golf ball at the top has a mis-match in the mold - the two halves of the golf ball are not aligned. I would never sell a pen the way it is.
They do seem to do a lot of knock-offs of other manufacturers and some others that to me are "gimmicky" (but Penn State has quite a few that are gimmicky also). I've typically avoided these kits.
A few that I wouldn't hesitate to buy are the Sierra, Ultra Sierra, Gallant, Cigar and Magnetic.
As noted by others, even though they might look the same as others the parts are not necessarily interchangeable. Whenever I order a new type of kit I always order the bushings. But their bushings are usually around $1.00