I think that a 20/30% deposit is fair but only if you do all your research on the maker up front- I look at giving a deposit for anything as the responsibility of the buyer to research the seller, even then, things can and will occur beyond anyone's control- so there is ALWAYS risk in any business transaction. Seems like health issues for older cue makers or their family members has been the single biggest reason given when cue orders are going unfilled- so i do sometimes worry about dealing with an "over 50" cue maker", only for that reason. One of the most important things i have learned is to make sure EVERY aspect of the cue being built is discussed, agreed, and placed in writing via at least an e mail- I have seen cues from top makers where the inlays in the points do not line up 100% with the matching inlays in the butt sleeve- some off by 3/16 of an inch!! to me, that is a flawed cue that needs a redo and I would demand that to be done. Other issues like balance point, butt and shaft diameter/taper etc. need to be clearly agreed upon upfront.