Ballast for friend's boat.

I don't have my own boat and I want to add ballast to my friend's boat. I figure I am stuck with the cost of sacs but is there another option for pumps out there. 125 bucks just seems like a lot of money for what looks like a fish tank pump. What pieces do I need to get the sacs filled? i.e. hoses, nozzle attachments? Any help would be appreciated. Sorry if this is a re-post, but all I have foud so far is schematics for thru-hull systems.

Go to walmart and get pick up a 750 GPH 12 V pump for 19 bucks. While you are there pick up some hose, clamps and the pipe fittings to connect to the screw on side of the pump while you are there, 10 bucks. Find a cigarette power adapter, 3 bucks (or free if you have the one for your last cell phone laying around). 2 blue end water bed valves from your local waterbed dealer, 10 bucks. Enjoying the 45.00 pump you just made from walmart and feeling good about supporting a company that leaves a wake of out of work illegals and out of business small businesses - priceless.
Unless you just drove 5 hours to get all this stuff.