Here are some choices I've made in the knife making business. I am only a part time/hobby maker, but I have not been without open orders for over a year. I am on track to send out 6 knives in the month of June. So consider my choices from that perspective.
1) Don't take money up front. [Caveat-if you're building "high end" customs to the point where material procurement is a thing, i.e., legal ivory, that is a pure business matter with your client. I'm talking about deposits/pre-selling for garden variety stuff.]
2) First right of refusal. I am not bound to sell to a specific buyer, the buyer has "dibs" but may refuse the piece, no harm, no foul. I sell to someone else. This works well with (1), and allows the maker to stay in their lane.
3) No price drops, ever. If I list it, it sells at that price or I get a new knife. I'm too cheap anyway.
4) No "waffles." Raffles are for charity. Selling chances on a knife (or anything else) for profit is sub-human. It's like one of those scam penny auction websites.
After all that is followed, I quote a knife at full price. And sell most of them at that. But, if this is a 3rd/4th/5th for the same customer, I have knocked $25 off the invoice. But I never would advertise or offer that up front.