I have...
... a Hunter 28.5 with an iron keel. Some people go to extremes to control rust, others are more minimalist. I have found that maintaining the keel is no big deal. Check the archives as there is lots of info there. In sum, grind or sand it yourself. Use a grinder, wire wheel, coarse grit disks, or whatever is handy. I wouldn't bother trying to get the whole keel down to bare, shiny, metal and barrier coating. Rather, knock off as much rust as you can, coat it with POR-15, and then bottom paint it and then go sailing. On my boat, this is an annual affair that takes less than an hour. You've got better things to spend $3500 on....