As adoption grows the fiat to BTC volume rate will still be relatively small. Thus the price will be open to manipulation. It seems like the exchanges are a liability to BTC price. How will we solve this?
Unless we get to a stage where BTC become the standard currency, we will always have price manipulation because of low volumes on exchanges.
Arbitrage prevents price manipulation.
If one exchange tries to raise prices, traders will dump on that exchange and profit from the manipulation.
If they try to lower prices, traders will buy cheap from that exchange, dump elsewhere, and profit again.
Attempts to manipulate prices outside of normal order flow will just hurt the exchanges.
arbitrage does not occur in reality. this has been pointed out to you before that bank wire transfers are not instant so if a price falls, no one can instantly deposit funds to then eat up a cheap deal to raise the price to normal.
what does occur is when one price gets manipulated, people on other exchanges panic sell. and that is the point the OP is making about exchanges being a liability.
the last time that arbitration was truly successful was where bitinstant took a risk on being a medium of dollar swaps between exchanges. i would say that in some small way ripple can fill that void, but not all exchanges are connected to ripple to allow successful and instant arbitrage to the same extent that bitinstant did between the exchanges of 2012.
now moving to the OP's question.
right now the best thing people can do is use localbitcoins and OTC style systems where actual bank account movements are instantly recognisable against bitcoin movements. and for people to base the value of their buys and sales based on their local and personal supply and demand. ignoring the movements of the crappy PHP exchanges (as we know they are speculative/manipulated). then when circle fully opens up its rates and when things like the winklevoss trust is running which is when true transparent value can also be seen alongside localbitcoins/otc. then we can have a better guage of true value.
until then i feel that the crappy exchanges are undervaluing on purpose, in an attempt to buy up cheap hoards ready for when the proper, scurely and transparent market exchanges are fully operational.
i do feel sorry for anyone selling at losses, and selling at undermarked prices. but that is your own choices and no one else can be blamed for you pressing the sell button