depends on your list.
For a skink cloud, no. ...or..actually maybe.....but no until someone disagrees with me
for a combat list with as few drops as you can keep in the 6'' bubble: OH YES.
Use the engine to back up your skink priest's lore, and dont use the bound spell except in favorable situations.
Ive had good use of it standing between 2 blocks of 8Krox, also covering the skink screen in front.
Nitting 1/6 of all wounds in your army is well worth the engine cost.
The real question is: are you bringing an ancient anyway?
The extra points are well invested if you do, but if you weren't planing to its over 1/10 of your army you are investing just to get the engine, and then you should consider if those points are better put elsewhere...(there might not be, just consider it)
See the engine as the cream on top of your already purchased Stegadon cake.