Proposal Ideas

I've got a few days before my next proposal but I wanted to get people's opinion on this first. (feel free to steal if you want too by the way):

New Building:
Name: Giant Shield (or GS for short)
Max Hit Points: 500
Attack Strength: 0
Attack Range: 0
Armor: 10
Special: Players may not occupy squares which also contain a Giant Shield that they do not own. Squares may contain only 1 Giant Shield at most.

New Command:
Name: Build Giant Shield
Enchantment: No
Duration: N/A
Can Be Issued To: SCV
Cool down: 4 days
Effect: The player pays $500 and gains a new Giant Shield at the location of the issuee.