Cardeer, If you have medical clearance (just a note from a doc usually works), an x-bow is allowed during the entire MD season. Without clearance, there is a 2 week period (I think in November) in which anyone can use crossbows. As far as price of license, it went up this year, and is a hefty $130 for any non-resident for just the license. A $25 bow stamp is also required. MD did sell 3 day licenses at one point, but I'm not sure if they still do, or if they do how much they cost.

I hope this helps!

Slice