Not an exact answer to your question, but here are some references for you.
Level 4 characters should have about 6,000 GP worth of stuff.
Level 6 character should have about 16,000 GP worth of stuff.
Level 7 characters should have about 23,500 GP worth of stuff.
There are some level 4&7 Pregen characters HERE that you can look at to get an idea.
What do you think:
What magic items are appropriate for a group of 6th level PCs?
Rogue, Ranger, Fighter, Cleric, Mage, Sorcerer
Depends a lot on the setting and how prevalient magic is. If it's a magicmart setting (all magic items are available for the right price) and you're using typical Wealth-by-level (16000 for a 6th level character), I can make some general suggestions, but it depends a lot on what builds they are.
Rogue: 2 +1 weapons (2000 each), +2 armor (4000), +2 to saves (4000), +2 Dex (4000), 2000 left over.
Ranger: Either the same as the rogue or the same as the fighter.
Fighter: +2 weapon (8000), +1 armor (1000), +1 to saves (1000), +2 str (4000), 2000 left over
Cleric: +2 Wisdom (4000), +2 armor (4000), +2 to saves (4000), Two CLW wands (750 each), 2500 left over
Mage: Magus? Wizard? Either the same as the sorcerer or a hybrid of the sorcerer and the rogue, except with a +2 Int item
Sorcerer: +2 Cha (4000), +2 bracers of armor (4000), +2 to saves (4000), 1-2 wands (attack if the sorc has utility spells, utility if they have attack spells) (750-1500) 2500-3250 left over.
With any of them except the fighter you could drop saves to +1 and bump armor to +3 (or do the reverse) by spending 2000gp from their leftovers. The leftover funds should be spent on one-use consumables like potions and scrolls, alchemical items, and the like. Don't forget the cost of actually buying the weapon and the armor.
Typically Big Six + Handy Haversack.
Rogue - (assuming TWF) +1 leather (1000), 2 +1 weapons (4000), +1 resistance (1000), +1 natural armor (2000), +2 dexterity (4000), Haversack (2000), +2 protection (2000)
Fighter (assuming thf) - +1 plate armor (2500), +1 melee weapon (2000), +1 resistance (1000), +1 Natural Armor (2000), +1 Protection (2000), +2 strength (4000), Haversack (2000), Masterwork strength bow (500)
Cleric (assuming sword and board melee cleric) - +1 weapon (2000), +1 armor (1000), +1 resistance (1000), +1 shield (1000), +1 Natural Armor (2000), +1 Protection (2000), +2 wisdom (4000), Haversack (2000), 1000 for miscellaneous.
Wizard - +1 saves (1000), +1 protection (2000), +1 Natural Armor (2000), +2 int (4000), lesser extend rod (3000), 2 blast wands (1500), Haversack (2000), 500 miscellaneous.
Ranger can be built per fighter or rogue, sorcerer as per wizard with +Cha instead of +Int probably no lesser extend rod.
Pearl of Power begins to show up about this level but isn't a standard build option quite yet. Boots of Striding and Springing are somewhat common at levels 7-10 but the price tag associated with them is a bit steep at 6th level.
Obviously in most scenarios the entire party do not need haversacks full of survival gear, I pretty much assume at least 50% of PCs have them by this level though. People without them have probably boosted either resistance to +2 (4000 GP) or maybe have a back up magical weapon.