With all due respect, I can buy a kit on iFixit for $55 for an iPhone 16 pro max, including the battery. I’ve replaced my iPhone battery before, aside from the glue being a bit sticky so needing a heat gun it isn’t that difficult.

The actual cost breakdown for a battery replacement is:

  45 EUR for a new battery
  10 EUR for new display adhesive
  20 EUR for screwdrivers and a spudger (unless you have them already)
  a suction cup and tweezers you probably have at home already

Ignore the 25 EUR clamp and 20 EUR heat pack, I did and they weren't needed at all. So all in all, around 910 USD less than you claimed.

The heat gun discussion in the sibling comments is also completely ridiculous. There must be 100 ways to do it without a heat gun. Put it on the radiator, use a heat pack for muscle soreness, or just borrow a hairdryer.

If somebody's unable to replace their iphone battery because they can't come up with a source of heat, I doubt they'd even be able to replace the batteries in their TV remote.