A BGA can be replaced with a freaking heat gun from Home Depot and some solder braid and some flux.

Source: I used to repair cable boxes for CTDI. While everyone else is using their Metcal station and wasting 5 minutes, I've got the BGA off, board deballed, and a new BGA package installed and ready for PKI in less than 45 seconds with a heat gun.

Not that much. BGA chips aren't that hard with a hot air station. I've done plenty of de-soldering and reflow using just a hot air gun.

Not really, you can learn to handle BGA in 4-7 days and $2-3K from some very best people in the business https://www.ipadrehab.com/index.cfm?Page=Practical-Board-Rep...