Hello and welcome, one and all! These are my ideas for Support-focused Income Items. The following are finished items thus I'll make notes as I move along. 

P.S. I don't know how to appraise item values. Hontoni Goumenasai. 

Bag O' Potions/Potions Bonanza/Potions Ever Ever After

Stats: 5/10/15 Health Regeneration, 5/10/15 Mana Regeneration, 3 gold per 10 sec., 0/0/10% Cooldown Reduction.

Unique Passive: Gratitude: (All) Gains charges every 30/25/20 sec. Each damage nearby allied Champions receive from Champion-based auto-attacks reduce this charge time by 1/1/1 sec. Charges cap at 2/3/4. When you heal or shield a Champion, you expend a charge to gain 5/10/15 gold and you and your target gain 3/7/10 bonus Armor and Magic Resistance for 5 sec. Triggering a charge sets off a 5 sec. cooldown before another can be triggered. 'Gratitude' can only affect one Champion at a time but can be set off altogether when the heal or shield allows it. 

Unique Passive: Emergency!: (PB and PEEA only) Gains a charge for every ability-based heal or shield you make to a Champion. Charges cap at 3/5. Charges refresh to max when visiting Summoner's Platform. 

Unique Active: Emergency!: (PB and PEEA only) Expend a charge to restore 100/150 Health and 50/100 Mana plus 1/2% of their max Health and Mana over 10 sec. to a target. You cannot affect that target until the restore is over. This ability can be self-cast. 5 sec. cooldown. 

Druid's Gift/Council's Blessing/Nature's Reawakening

Stats: 4/7/10 Armor, 4/7/10 Magic Resistance, 40 Movement Speed (NR only), 5 gold per 10 sec., 0/0/10% Cooldown Reduction.

Unique Passive: Eyes Of The Forest: (All) Walking into a brush marks it with 'Eyes Of The Forest' which grants vision inside and around that brush for 10/20/40 sec. and grants you 5/10/10% bonus Movement Speed for 5 sec. and 8/8/10 gold. Triggering the speed and gold grant sets off an 8 sec. cooldown. Enemies with an item categorized as Gold Income can shut down a revealed brush by walking into it and you cannot mark it again for 10 sec. You can only mark 1/2/4 brushes at a time. You can trigger the speed and gold grant even if you have reached max brush capacity. 

Unique Active: Forest's Aid: (NR only) Target an area to summon a temporary brush for 5 sec. Allies inside the brush receive 15% damage received reduction for 5 sec. Enemies inside the brush receive 30% slow for 3 sec. Entering the brush again refreshes the effects. Summoned brush functions the same as standard brush. 60 sec. cooldown. 

Mines' Blueprints/Mines' Deeds/Haunted Mines

Stats: 50/120/200 Health, 2/5/7 gold per 10 sec., 0/0/10% Cooldown Reduction.

Unique Passive: Prospector: (All) Gains a 40/80/120 damage-absorbing shield when out-of-combat for 20/20/10 sec. Active Mines grant you additional 2 gold per 10 sec. and plus 20 to 'Prospector' shield.

Unique Active: Network: (MD and HM only) Target an area to summon a Mine marked as entrance and another Mine within 1000 range of the first marked as exit. Allies can stand near the entrance for 3 sec. to instantly appear at the exit. Allies receiving Champion-based damage reset their 3 sec. countdown. Allies attempting to travel through the Mine are revealed to enemies within 3000 range. Mines are permanent and reveal a small area around itself but enemies can see them and destroy them with 3/5 auto-attacks. Destroying the entrance or exit destroys both ends. 'Network' can only be used while out-of-combat. You can only have 1 Mine at a time.  Cooldown begins on Mine placement. 100/100 sec. cooldown.

Unique Active: It's Haunted!: (HM only) Within 30 sec. of placing the Mines, you can reactivate to detonate them and summon 3 Skeleton Miners from both entrance and exit to help push the nearest lane or assist in attacking an enemy. Skeleton Miners deal 10 true damage in melee range and take 3 hits (1 from towers and Champions) before dying. Skeleton Miners last indefinitely until destroyed. 

Dark Pact/Dark Gift/Demon's Patronage

Stats: 4/7/10 Armor, 4/7/10 Magic Resistance, 10% reduced damage from non-Champion-based sources (DP only), 0/0/10% Cooldown Reduction.

Unique Passive: Unholy Presence: (All) Applies 'Unholy Presence' to up to 1/2/3 nearby allied Champions which grants 7/13/20 Attack Damage and 7/13/20 Ability Power. You gain 1/2/3 gold when 'Unholy Presence'-affected allied Champions auto-attack enemy Champions. You gain 5/7/10 Mana when 'Unholy Presence'-affected allied Champions use abilities. 1000/1000/1500 range.

Unique Active: Sacrificial Lamb: (DP only) Target an ally to mark it with 'Sacrifical Lamb' for 5 sec. and will transfer 100% of the damage they receive unto you. You can die from this. If you survive, you regain 30% of your max Health and Mana over 10 sec. Receiving Champion-based damage while regaining Health and Mana reduces duration of restore by 2 sec. up to a cap of 6 sec. This ability cannot be self-cast. 90 sec. cooldown. 

Immoral Stones/Defiled Remnants/Damnation Obelisks

Stats: 60/140/250 Health, 10/20/30 Attack Damage, 5/7/10% Life Steal, 5/7/10 true damage against monsters, 0/0/10% Cooldown Reduction

Unique Passive: Revenants: (All) Auto-attacking generates 5 stacks. Abilities generate 10 stacks. At 100 stacks, you create an aura around the first non-Dragon, non-Baron monster you attack which marks it and nearby monsters. Killing them leaves behind their ghost for 30/60/90 sec. These ghosts deal no damage, receive 200% more damage and grant no gold or experience to enemies. Ghosts do not delay actual monster camps from spawning. 

Unique Passive: Mea Culpa: (DR and DO only) Ghosts made by 'Revenants' can be killed again by you or allies, giving 25/30% of its original gold and 15/20% of its original experience amount. Monsters with buffs will grant their buffs but only for 5 sec. 'Mea Culpa' can only be triggered once per monster camp.

Unique Active: Cult: (DO only) Activate to grant yourself 40% bonus Atttack Speed for 5 sec. and you generate an aura that applies a 30% slow for 1 sec. to enemies who attack you. Aura lasts for 7 sec. 90 sec. cooldown.