The high price provides room for heavy discounting once the initial demand subsides.
It's all about matching supply to demand. Apple has priced past phones too low at launch leading to long lines at stores, long waits once initial stock sells out, scalpers worsening the situation whilst pocketing handsome profits at the expense of Apple's regular customers.
Wait a few months and you'll get $200-250 off at resellers (but not at the Apple Store, obviously). A few more months and it'll be $300 off.
Patience.
Patience? Apple goes through this same conundrum every single year where they have shortages of iPhones and you can't tell others that Apple can't figure it out when it comes to supply and demand. How many years has it been in a row where Apple has either sold out or they do not have enough iPhones for a proper launch? And then you're suggesting year after year everyone should have patience? Or maybe Apple could rectify the appropriate supply for a sufficient launch.
Not To mention, you're saying wait a "Few months". That Sounds a bit undermined and modest to me. Do you have any idea the pent-up demand for this next iPhone is going to have? A few months? Try more like well after the holidays somebody will get their hands on the iPhone 8 if Apple brings the appropriate changes. The Next iPhone is going to shatter any record the iPhone had previously at launch and the demand will be in extreme numbers.