Quick take
A dedicated whole-house iron system commonly falls in the low-to-mid four figures before installation. Combined iron, sulfur and softening projects can cost several thousand dollars.
Dedicated iron filter
Air-injection and oxidation-media systems are common for significant dissolved iron and usually cost more than simple sediment filtration.
Iron plus manganese or sulfur
Each additional chemistry problem can change media choice and system size. A broader treatment system costs more but may avoid stacking multiple poorly matched filters.
When a softener is also needed
If hardness is high, dedicated iron treatment followed by softening can be more reliable than expecting one softener to solve both problems.
Testing saves money
Iron concentration and pH determine whether a quoted system is appropriately sized.