No brainer really - stick with your Golem. It should be well worth the dust invested into it, even if you have to grind a little bit more to get to the same level as the Geodude.
The Geodude is too much of a gamble, even factoring in the TM, then you'd be left with zero candies on which to develop it further anyway. Dust you can get from anywhere, even if it is scarcer these days; Geodude candy is a little harder to come by.