Well, considering we're both in DIV, I think I have some knowledge about this subject. Also, my PG is my best player on my team (even though he averages 10 ppg and my other player averages 29).
You won't be able to get a good DIV PG for $500k...try to go around the $900k-$1M mark and get a PG that will actually last (the type you can play in DIII). Perhaps you should sell your SG to gain some extra money? idk.
Here are some considerations before you get a PG.
Are you outside or inside oriented? Outside teams will want a PG to be a shooter as well. Inside teams need a primary ball-handler/passer that can drive as well.
Do you need a great outside defender or not? Most competitive DIV teams, in my experience have 1-2 great offensive outside players. You'll need to stop these, not only to stop the players themselves, but if it's an inside-oriented team, you will need to have more defense on the passing lanes. Some teams will pound a $40K center and have decent PG/SGs. A good OD will make sure these beasts won't get the ball every play. If you already have 2 good outside defenders (prolific+ imo), then fine. If not, make sure the PG you invest in has it.
How good of a passer do you need? This again, is related to the outside/inside oriented. Inside needs a much better passer. But even outside teams sometimes need a passer. For example, I have a PF that can shoot the ball but can't drive at all. He seems to really benefit from my PG. In general, I'd say outside needs a 9-10 passing while inside needs a 10-11 (I have 12, it doesn't seem to help ALL that much).
Age I'm a strong believer in buying older players. You're looking for somebody that can help you win now. Age gives you better skills and more experience (and in general better stamina and FT as well). By the time you get to DIII, you will want to upgrade your PG anyways. Sure, you lose a lot of value from an old player, but I think winning in DIV NOW is more valuable than losing 100K extra in DIII.
Now, when it comes to specific skills, I think the PG is basically a well-rounded outside player. So you're basically looking at a player like this (if you want to get a good PG, bump up the numbers by 2 pops).
Jump Shot: Prominent Jump Range: Proficient
Outside Def.: Prolific Handling: Prominent
Driving: Prominent Passing: Prominent
As you move up to higher levels of PG-ness the JR, passing, and handling can be less than the other skills. Also, bear in mind that, based on my first question, you want to adjust the balance toward certain skill sets.
Of course, I've only been here for 3 full seasons and have had only one team to experiment (and only one PG since the beginning). I think that, based on my one PG's performance in different situations with different skill sets (I am still training him), I've gotten a pretty good feel of what a PG with different skill sets can do and is supposed to do.