I want black buttons for Player1 and Player2 - there's not that many places that sell them and they're a bit difficult to track down. I found a place that has them in stock and they responded very quickly to my email requesting whether they had the items in stock.
Lizard Lick Amusements has them for $1.50 each which is very reasonable. It's shipping that's going to get me in the end if I keep ordering from different places. But that's okay - some places have stuff, some don't - I'll order parts where I can find them. I just placed my order and was emailed that they'll be shipped tomorrow.