finding multiple shapes that "could" CONTAIN single shape defined on another layer

Hi!
I have created PostgreQSL +PostGIS spatial database with 2 different shape files, PostGIS imported. (and few tables)
I had some issues with PostgreQSL +PostGIS and ArcGIS 10.1 so I have decided to move to “local” analysis by just importing complete 2 shp files with standard geom column and so on.

With my projection I can count area and have XY coordinates, ( not lon- lat ).

Layer A have sth like 500 parcels.
Layer B only 1 big parcel.

Intersection gives me exactly what I want – shapes that contain my big shape and then I can count my LANDVALUE column in selection (by intersection). I am interested in the lowest selection value among all possible selections (in layer A area) of multiple shapes that "could" CONTAIN single shape.

But I cannot move layer B and look for intersections every few inches …
Please give me a clue Is there any smooth solution for example with PostGIS querying or using model builder with loops ?
I tried to find something but failed.
Best regards,
Michael

(I`m running trial version 10.1 for learning purposes)