We had many great meals during our visit to DLR last October, and Y Arriba Y Arriba was one of them. Probably the most comprehensive DLR menus online is at
www.mouseplanet.com though they don't date their menus like
www.wdwig.com does, so keep that in mind.
Their menu consists of tapas (appetizer-sized portions) from various South American countries. I'm pretty sure that even non-adventurous eaters can find things to their liking on the menu. We ordered 4 things: the Churrasco, a steak in a sauce with marinated tomatoes ($10.95), Entremeses, which to me is best described as an antipasto platter ($9.95), a side salad that we shared ($5.95), and a side order of Totopos, which were very fresh tortilla chips with guacamole and salsa ($4.95). This was shared among two adults, and we were satisfied. We probably could've eaten one more dish, but we were happy with what we had. Everything was delicious! The atmosphere is nice, and there were latin-themed dances every 15 minutes.
If you look at the Restaurant Reviews on the top of the page, you can read some reviews. I included the prices in mine for all the restaurants, so maybe that will give you an idea of what to budget. The mouseplanet menus should help too. Also, we ate mostly at sit-down restaurants, so that's more expensive.