So this is actually covered in the Owner’s Manual, FAQ, and other supporting documentation. Auction mechanics are as follows: No traditional hardcap or soft cap because of the descending price auction. The Initial supply auction will last up to a week, with 8 million MET available for purchase. The starting price in the initial supply auction will be (an intentionally high) 2 ETH per MET, and it will descend by 0.0001984320568 ETH every 60 seconds toward its (intentionally low) floor price of 0.0000033 ETH, as long as the auction is open and there are still MET available for purchase.

So market price is discovered via a descending price auction.

Should a purchaser deem a given price too high or unfair, they can wait for the price to descend to a level they agree with and purchase then — provided there is supply left

You can read more about how descending price auctions (specifically the daily supply lots) work here: https://medium.com/@MetronomeToken/what-is-a-descending-price-auction-8c0770bb6a71

You can check out the quick glance price chart (for the initial supply auction) the team put out here: https://medium.com/@MetronomeToken/metronomes-initial-supply-auction-quick-glance-price-chart-c9132595871e

No maximum or minimum purchase outside of gas requirements for a successful transaction.