I bought the above pictured $10 set of Chaos Cultists with the intention of using them for some conversion work. Ultimately I wanted to make some primaris psykers and ministorum priests.
While not yet painted the below Ministorum Priest was created using the model pictured in the bottom left of the above photo. It took a great bit of chopping, green stuff, and bits, but here it is.
The robe, rope, censer, book and purity seals are all green stuff. The pole is styrene rod, the pointed bottom is cut from a disposable glue applicator the top is made from two Forgeworld Inquisition icons. The head is from Maxmini.