About waiting for a decline - this assumes that a decline will occur. Whether or not it is rational to enter at the current price, or wait for a decline, is a classic recurring trading dilemma and can easily be solved with a bit of logical thinking.
The assumption here is that we've already seen the capitulative final move down, and the ultimate lows are in. In my view there's a real risk this isn't so - at least a 10-20% chance. In Argentina 2001 there was a clear climax - a currency devaluation, sovereign default, and forcible confiscation of bank deposits (via conversion to depreciated Pesos). We never really saw this in Greece. You can plausibly argue that the Greek debt is going to be indefinitely funded, extended, and if necessary simply written off by the Troika, and therefore there's no real difference - but the debt is still there and unexpected political developments could easily make it become relevant again.
Additionally, Greece currently lacks the economic tailwinds enjoyed by countries in many historical examples, such as spare 'runway' for credit expansion to once again take hold and boost economic activity, and a strong regional/world economy to boost FDI, exports and growth. This doesn't mean that share prices won't or can't increase, but it seems to me that the upside is less which demands a more conservative strategy.
Lastly, at this point the likely payoff is 2-4:1 - not bad but not the numbers we were looking at 18 months ago.
On the other hand, if a decline does occur (which presumably will be accompanied by market stress/turmoil more generally) we will have a chance to gain far more clarity on these risks, as well as a potentially much more favorable entry than at present.