the light rail runs from bwi to close to the PA border.

http://www.mtamaryland.com/services/...6LightRail.pdf

hotline and I think priceline both show hotels on a map. if you overlay the two, you should be able to find something close to lightrail. seems prices for that weekend are very high. not surprised. baltimore does not have an excess of hotel space.

I do not know what you consider inexpensive, but if you do a search on orbitz for hotels at bwi, there seem to be over a dozen under $120.

don't know what you use for basis, but under $120 in dc/balt area in summer is getting down there.