even if a qualified charity. what you are contributing is ordinary income property. The amount you can deduct for a contribution of ordinary income property is its fair market value minus the amount that would be ordinary income or short-term capital gain if you sold the property for its fair market value. Generally, this rule limits the deduction to your basis in the property. it is unknown what the IRS would deem your basis in the unspent $150. it could be $0. or it may be proportional $250/$450 * $150 = about $83.
