I keep getting my conveyors mixed up as well as placing things incorrectly and notice you only get refunded for a portion (1/2) the cost of the item.
It would be nicer if when you bulldozed a recently placed item you would get a full refund, alternatively a plan mode where you could place ghost items to plan your production line better would help.
Both seem like good ideas to me. One possible way of defining “recently placed” would be “you’re paused, and placed the item during the pause.” I don’t know about others, but when I’m doing non-trivial work, I tend to do so while paused. At least until I’m so filthy rich that I stop caring about being frugal. 
Good idea, trying to make fair logic would be a pain.
i.e. Do we count the last 10 items (in which case expensive but few items could be abused)
or do we put a timer on it, in which case building slowly could be costly
So entering pause/build mode could just lay everything down and not cost any money until you unpause, then everything is placed and money is removed. I don’t know how the game is coded in the slightest but as long as the buy and refund are locked when pausing then this should be “safe” to do without being able to abuse?
make part of game difficulty 100% 75% 50% 25% and 0% refund