The price is good, and may not pass Hilton's ROFR process. But you should take your time and monitor sales prices on the TUG Marketplace. Kings' Land has good high point properties, but maintenance fees are high (but comparable to Kohala). You also need to decide how many points you will realistically need, since going over the 7,000 point threshold gets significantly more expensive. If you go to Hawaii a lot you will need a lot of points, but if not, perhaps 7,000 or less would suffice.
Regarding 2019 points, don't count on those. The 2019 maintenance fee (for 2019 points has already been paid), so I'm don't know why they say you have to pay the maintenance fee to get those points. Also, you won't really know if those points really exist until you get the Estoppel report from HGV. Frankly, it's too much to deal with before 2019 ends to count on those points. If it happens, great, but a lot would have to happen quickly for you to be able to move on these 2019 points. The owner may try to convince you to let them book a trip for you in your name with these remaining points, but again, what a complication this will add to your buying situation.