Hey there, this isn't really an issue of pre-market.
First off, there is a very big difference between the offer price and opening prices. The offer price is set by the underwriter, and this is typically what investors on the primary market (banks, brokerages) etc will purchase the stock for. These investors then turn around and sell the shares to retail investors like us on the secondary market for a profit.
Depending on the demand, that is what will spike the opening price, the one that we get. Buy orders will pile on top of each other prior to market open (but aren't executed), and depending on how much demand there is, that is where the stock will open at. If there was next to no demand, you'd see it open closer to the offering price.
Institutional investors do have a leg up on retail investors yes. But, they are the ones giving the initial capital to the company, and they're doing the leg work of selling the shares on the secondary market as well.