I just updated my personal sheet tracking these things. The parameters of that one:
- flat price 0.005 assumed until Mt.Gox opens
- for 7/2010-2012, Mt.Gox prices used
- for 2013, three exchanges
- for 2014, Bitstamp only
- daily VWAP
- first day 2009-1-3, the first day of Bitcoin; last day 2014-7-9, the 2014th day of Bitcoin

The exponential trendline for this time:
USD/BTC = exp(-2.869800 + 0.003012 * D), D being the number of days

R^2 = 0.934183

The trendline is at $1583.

At $623, we are currently -0.405 units below the trend.

For comparison, the max we ever went below the trend prior to the first 2013 runup, was -0.573.
Prior to the second 2013 runup, -0.341.


The maximum downside (greatest drop in price experienced ever after) after a day when price has already been at a low of -0.4 or lower, is -19%, experienced in 2012-10-5 to 2012-10-26, when the price dropped from $12.75 to $10.31.

This is comparable to the price going from $623 to $504 this month. This would put us on par with the maximum historical downside from already such a low point as $623 represents in the trendline.

I will not go to the upside calculations now, just leave the closing remark:


TL;DR: Historically, buying at a price such as this has represented a very low risk entry point with very limited downside in dollar terms.

Historically, selling at a price such as this (for any other purpose than covering immediate needs) has been counterproductive, as it is very likely that you will get a better or at least not much worse a deal; 1, 2, 3, 6, or any number of months in the future.

they didnt get his email. it was a forum inbox message

these things happen alot. in the past it has been found that scammers prep their list of 'marks' by asking forum topic questions such as:
"how much bitcoin do you own"
"what wallet software do you use"
etc

these info gathering games are what scammers do to target the right people. after all there is no point phishing someone if they only have satoshi dust to their name. and theres no point entering into conversation with them to tempt them to download trojans if the scammers code is not compatible with the victims wallet.

so usually scam emails and private messages are targetted to the victim, because the victim has made some form of admission that he is worthy of being scammed. either admitting wealth, admitting he runs a wallet that is compatable to a certain tojan or the fact that the victim admits to not have 2FA on their other logins or lastly, they have been scammed before so are proving to be an easy 'mark'

Google:
how do I buy


look at what comes up