Aaah, but that was back in the day when The Emperor Braben, may we bask in His Greatness, said the game was going to cost 10 quid and each expansion 5. Wait until FDev send around the collection agency to notify you of the changes and the markup owing. Shurely they aren't selling the same 10 quid game for 60, and a 5 quid expansion for 60 with the same amount of (incomplete) content?
A few possible reasons.
1) They discovered the cost of developing a game of this scale was much higher than they expected (might seem hard to believe with experienced people in control, but in software development one of the largest variables is estimations of development times for a peice of functionality... and of couse, clients don't want to hear "well, it might take anywhere between 1 and 100 hours to implement")
2) They discovered through kickstarter there was less interest than they expected, so knew sales were going to be lower, so had to jack up the unit price to cover development costs (possibly a little more believable, but wasn't the kickstarter there to judge interest levels before they went to get more from private investors?)
3) They realized their initial price assessment was way off - or the finance guys had been screaming at Braben that no way could they do at that price and finally got him to understand this.
4) Their planned scope for each release got bigger and bigger. With the DDF going full tilt, they ran into scope creep. Suddenly what was planned as a 10 euro game became a lot more expensive.
Or perhaps a combination of factors, which in business is often the case.
Personally, i don't care what the reason is, i know the business very well and know how hard it can be to get things right. As a customer i only care that i'm getting value for money. At over 600 hours for 60 Euro, i'm totally cool.