I also think that Teleport Mastery should be maxed first. But here's what my brother did at the earlier levels of 3rd job (he was already 7x when BB came out, so I won't be adding levels):

3 Dispel <-This allowed him to Dojo occasionally (he finds it fun), and also the ability to add to Holy Symbol if needed
Max Teleport Mastery <-Increase distance and an extra attack
Max Shining Ray <-Several reasons for this. First, Heal cannot be effectively tele-casted, or else we're both doing it wrong. Next is the issue with the people at Jesters; where a Priest can easily take on the whole map he was given the top left platform and had to wait for the spawn while the others killed slowly, as well as constant KS wars. He used his SP Reset to convert from HS to SR to avoid constantly putting up with this. Also, it allowed him to explore more of Maple, eventually putting him into Ariant where he found all his potential mage equips (being unfunded) and gained about 100% per hour soloing some map in Magatia, without having to put up with KSers and jerks. Also allowed variety in training, as he wasn't limited to undead monsters.
8 Dispel <-5 Dispel was the original plan, but putting it up to 8, and combining with my CO allowed just the two of us to pass Manon, then get 1/1'ed at Griffey because we didn't know what it's 1/1 looked like
Max Holy Symbol <-We started training together for a bit. Also worked to get him into Hoblin PQ at lower levels, but then he decided that it was a waste of his time
Some points on Door <-I'm not too clear what level it's at, because we lose track when I use CO, but just enough to be practical
1 Dragon <-After the shock of realising that Bigfoot was Holy immune, he put a point into it, the tele-casted Magic Claw. 23 Bigfoot solos later and he never found a toe, so he quit
Holy Focus <-It's not maxed yet, but it's just for the criticals

I'm not recommending this as an absolute build itself, I'm just trying to point out that a HS first build is not the only way to go. Of course there were a lot of personal influences, but he did fine without HS. Partying is fun, but partying with misinformed jerks is not.


Also, I recommend Ghost Ship 6 from 100 upwards. Not as crowded as MP3, but still a good 60-70% per hour solo, keeping in mind he has only clean equips (so every other Priest is gonna be faster than him). Also close to Capt. Latanica, which is nearly 20% in about 5 minutes (going in twice per day). Truthfully, he gains about 75% per hour because of Capt. Latanica and the quests required for White Essence.