Yes, the $250.00 deductible per item is pretty steep. I had a housing flood last fall that killed my camera, lens and housing electronics. Housing repairs set me back $600.00. The deductible on DAN insurance is $250.00 for losses due to housing floods and $100.00 for other types of loss. Of course, these per item deductibles are clearly stated in the policy.
Based upon my experience, I recommend that anyone who's going to insure equipment keep copies of original invoices and receipts, and list those values on the policy. The cost of insuring will be higher because the insurance company's formula is based upon charging a flat amount for every $100.00 of value.
I had factored in depreciation for the value of my Nikon D7200 camera since it is an older camera and isn't really available new any more. Purchased new, it cost me around $1,200.00, but a low shutter count used one is around $700.00. The incident left me wishing that I had kept my purchase receipts and had insured for the original value.
Keep in mind that the insurance company settled without any hassles. But, I realized that I needed to do better with keeping documentation of my equipment expenditures and insure at the 'when it was new' value of the equipment.
I had carried an insurance policy on my housing and equipment for over ten years and complained many times about the cost of insuring my camera and lenses. The experience left me wishing I had insured for the 'when it was new' value rather than factoring-in depreciation.
I also recommend that people check to see if their home owners insurance will cover a flooded housing scenario. My home owners insurance agent laughed at me when I asked him about it. Still, I know underwater photographers whose home owners policies do cover equipment loss due to housing floods.
In the bigger picture of avoiding loss due to flooding, make sure you have a vacuum valve system and a moisture detection alarm that are working properly. Overall, these are pretty cheap insurance to avoid the expense of replacing flood-damaged equipment.
-Tinman