I voted NO. I didn't think wasting the $ on an incubator that will hold one clutch. That means one hova-bator per clutch...NOT practical.
This is what inspired us to make one.
http://ball-pythons.net/forums/showthread.php?t=86646
I went on Craigslist and found a FREE mini fridge that was OUT of freon. Hence no disposal issues. Removed all the bells and whistles and filled/covered holes. Used existing holes to run the probe and electric computer fan cord then sealed the holes with expanding foam. It was REALLY EASY. I'm sure you would have no problem making one. Just run it for a while before eggs to make sure its good to go.
Fridge - Free
Thermostat - $120 (Herpstat)
Heat Tape - $15 (I think)
Computer Fan - $5
Foam (one can) - $6
Aluminum Foil Tape - $12
Heavy Duty Extension Cord - $10
Ours holds 8 - 6qt. tubs.