If you buy this product you are investing in foreign developed market equities. So, if you do this, you have made a decision to: (a) invest in equities and (b) take on exposure to currency risk and well as market risk.
The first thing you should consider is how this product fits in with your overall asset allocation strategy, i.e. how much of your portfolio do you intend to allocate to equities; of that how much to developed markets; and of that how much to equities denominated in a foreign currency. Then see if this product fits into that strategy.
Or maybe you don’t have an asset allocation strategy, and your question basically is “If I invest in this product will it make me rich?”
To evaluate this product you need to know something about how the S&P performs, e.g. what is the probability the S&P will fall below 30% or will rise above 50%. Statistics on this are easily available, e.g. on page 274 of Ken Fisher’s book ‘The Only Three Questions that Count’, where you can find the S&P annual returns and the frequency that these returns have occurred since 1926. Mr Fisher provides the returns up to 2006 so it might be prudent to update his figures to take into account S&P returns since then.
You also need to have some idea on how the USD/EUR exchange rates vary, as this will also affect your return.
[Disclaimer: The above is comment / observation and is not a recommendation to follow any particular investment strategy or to buy / not buy any particular fund.]