tapas near copley/park street
I would double on Tapeo, with the nice weather this weekend try to grab a seat on the patio. Toro is also very good in the South End, although service can be dicey. I had a horrible experience and thought the food was sub par at Taberna de Haro so I can not say a nice thing about that place.
Tapeo on Newbury, a clone of Dali in Somerville: decent tapas, with good sangria, a long list of Spanish wines, and a nice patio.
Bar Lola, on Comm Ave: cute space, nice patio, bad drinks, horrible food.
Far better, but further afield: Taberna de Haro on Beacon Street, Brookline, and Toro on Washington Street in the South End.
I'm not sure I'd call any of these cheap. Tapas have a way of adding up.