Generally speaking in the US they are not allowed to invalidate a warranty d/t you doing your own work... Catch is you need to document it. IE keep your receipts on the materials and keep a log of when you did what. *This is not legal advice, I am most certainly NOT a lawyer, etc. etc.*
Had the local shop do mine, Est price was $280 US without the throttle sync, $430 ish with it. Labor rate around here post covid at 125 an hr. Found one place under that by a little, but they are scheduled 3 weeks to 2 mo out.