The low price tag is the trap
Green iguanas are famously inexpensive to buy, and that is precisely how people end up with a reptile they cannot afford to keep. The hatchling in a small shop tank is a few inches of lizard; the adult it becomes within a few growth years is a long, heavy, tree-climbing animal that needs an enclosure closer to a small room than a tank, with height to climb, branches stout enough to hold it and space to turn around. Housing that animal properly is the single biggest cost of iguana keeping, and almost nobody pays it on day one, because almost nobody buys the adult enclosure for the baby.
Instead, keepers buy a sequence of ever-larger enclosures as the iguana outgrows each one, spending more across the upgrades than the final home would have cost bought once, and still often ending up short of space.
Heat, light and the electricity to run them
An iguana is a tropical animal that must bask hot every day, in a home that is usually far cooler than it needs. That means powerful basking lamps, background heating for a large space, and ultraviolet lighting across the enclosure, all running for long days, every day. Ultraviolet tubes and bulbs are replaced on schedule because their output fades invisibly, so lighting is a repeating purchase, not a fitting you buy once.
The electricity bill for heating a big, warm enclosure through a cold winter is a real monthly cost, and it scales with the enclosure size you were trying to save money on. Cheap to buy, expensive to keep warm is the honest summary of this species.
Food and veterinary costs that grow with the animal
Feeding is fresh produce bought in adult quantities: dark leafy greens and vegetables in a daily bowl large enough that the weekly shop for the iguana resembles shopping for a person. It is not exotic food, but the volume is relentless, and it lasts the iguana's whole long life.
Veterinary care is the other heavy line. Iguanas need vets experienced with reptiles, and the problems of under-housed iguanas, broken tails, egg-binding in females and bone disease from poor diet or lighting, are not cheap consultations. A female iguana can also need veterinary attention around egg-laying even when she has never been near a male. Budgeting nothing for a vet because the animal was cheap is the commonest planning failure with this species.
The honest way to decide
Cost the adult, not the baby: a room-scale enclosure, a year of heating and lighting with replacements, a year of fresh greens at adult volume, and a reptile vet within reach. If that figure works, an iguana is a magnificent, rewarding animal. If it does not, the kind choice is a smaller species, because an iguana's needs do not negotiate down to a smaller budget, and rescues are full of outgrown iguanas whose first homes did the maths too late.
Start by knowing who would treat the animal, and KinsLe's Pet Services Directory helps you find reptile vets and trusted local pet services near you before you bring an iguana home.