This article was really eye opening for me http://www.mrmoneymustache.com/2011/10/06/the-true-cost-of-c... . I just started my first post college job and I made sure to move within biking distance of my work.
Highly recommended.
I'm in Ireland, and ETF index fund gains are taxed at ~40% each seven years, outside of your retirement fund. It seems like other avenues are more viable here in Ireland for wealth building before your retirement years, like running a business or maybe property ownership.
In NL we have (with respect to any kind of capital gains on private holdings) an incredibly fortuitous situation (no tax paid at all beyond a 1% per annum fictuous income, so that 1% of the value of your holdings gets added to your income which is then taxed at the normal rate).
In Ireland the index fund route may not be an option, but there may be other alternatives (such as direct real estate investments) that have a similar risk/return ration but a better tax picture. Your best advisor with stuff like this would be a local tax attorney.