Plus consideration and, more importantly to my point, intention. The use of the idiom "do as you please" would not intend the literal meaning of asking the other party to incur such costs and you agreeing to reimburse them.
But as I point out, do as you please is not a cut and dry case of it always meaning the negative, it can also be used as a positive but in a way to basically avoid any comment on the approach or subject matter detail. Which makes the comment somewhat open to interpretion.
Of course its often different when something is written in words compared to how it would come across in conversation, but again, leading back to that, don't do it verbally thing.
Consideration is, or would I would argue be taken as granted in the conversation between two people, one of which has caused damage to anothers property when the conversation is surrounding fixing that damage.
Rather than being smart, the OP is better off sticking with his reasonable approach.
Relying that a judge would dismiss the conversation as some sort of trickery using do as you please to mean something that is far from set in stone is considerably ramping up the risk, when as it stands right now, the OP is being reasonable and the other party isn't.
I disagree that moving to a position of being unreasonable is the best approach when continuing to act reasonably is probably best.
And, considering that the other party seems to use dubious English (just like the OP) I think trying to get tricksy with language is far from ideal.