Do you really need 5 separate power supplies? BG Micro has 24V fans for a buck a pop, and a 24VAC plug-in transformer for $8. Add a diode bridge, filter caps, and a 7824, and you can make yourself a 24V, half Amp or so power supply for about $13-15 (don't forget to include a heatsink for the 7824). You may also find a cheap surplus laptop switcher from the days when many of them had 22-24V supplies. Add a roll of zip cord to spread the power around, and you can do the whole thing for about $30.