Support items are the cheapest yet the have the most impact.
Let's see here:
2100 gold, heals entire team for 500
2200 gold, gives entire team 500-1000 shield
2200 gold, gives an adc 12% damage reduction and user massive healing
2300 gold, gives 4k worth of stats to the adc
Let's look at expensive items and their impact:
3600 gold, makes ap champs do about 30-40% more damage
3700 gold, makes ad champs do about 20-30% more damage and lifesteal 100 more per hit
3733 gold, gives some shitty combination of stats and movement speed
As you see, these support items have far more impact than expensive damage items, and we wonder why botlane has too much impact. These items are so cheap that supports often finish full build 10-15 minutes before solo laners. Also, these items are far more effective when used on adcs than other teammates. This is the reason why we sometimes refer to supports, specifically enchanters, as "adc slaves". It's also the reason why most adc mains have this "main character mentality" in which they think they are the centre of the team.
I suggest these price changes so they can reflect the impact of the items.
2100 -> 4500
2200 -> 4400
2300 -> 6000
These new prices will now actually be consistent with the true strength of these items.
who bought this item, now has 60 ap and +10% heal/shield power
shield strength = 282*1.1 = 310 hp = 827 gold
ad bonus = 46 = 1610 gold
30% attack speed = 750 gold
20 on hit damage = 500 gold
total = 3687 gold
This is an item that costs 2300 gold, and not accounting for the stats it gives to the user.