Dumbing this down for some:
(thanks for "on topic" responses from others)
1. go back to OP
2. this thread is ONLY about saving $$
3. it is NOT about terrorists, terrorism, politics
4. notice my pseudo? have been to 30+ countries, ~10 in last 20 mos.;
none charged over ~$20 for visa
5. A+B+C visas in S.A. currently = ~$420 total for US citizens
6. if YOU wanted to visit three major cities for only ~4 days
each & foresaw NO returns in next 5-10 years, wouldn't
YOU look for LEGAL ways to reduce $420?

To those staying on topic:

>>The ones using the EU passports used US passports to leave USA

Does US citizen born in US, parents born in US, no property outside of US, qualify for EU passport?

Found legal ways around some of $420 here:
http://en.wikipedia.org/wiki/Visa_re...tates_citizens
(enter Buenes Aires from Sao Paulo flight to local airport, fly out via EZE...?)
(enter Chile via Easter Island -- may not make sense $$-wise)
(why is Brazil missing from wiki link S.A. chart?)

Am using 100,100 Avios points to circle S.A. so limited to certain flight segments, but flexible on order of stops.

Do not further muddy this thread, think of others needing it in future...