I have vague plans to run a Pathfinder game using Roll20. It will probably be set in the city of Magnimar, and focus on low level play.

• Using the purchase method only.
  • 15 points to start with.

The following races are allowed: Human, Dwarf, Elf, Gnome, Halfling, Half-Elf, Half-Orc.

All those in the Core book, plus others to be determined.

No: Swashbuckler, Gunslinger APG: Magus, Warpriest, Witch ACG: Arcanist, Skald, Slayer

Prestige classes must be gained through roleplay, not simply 'levelled up' to. Prestige classes cannot be taken before 6th level.

Nope.

Magic items which require a caster level higher than 3rd are not commonly available anywhere (using the 75% chance rule).