Online selling etiquette

I put some stuff up for sale, it's a bunch of items that all work together, so selling it as a lot.

Put the stuff up last night before going to bed.

This morning I have three responses.

First guy: interested, send me a pm, I'd like to come see what you got.

Second guy: I'm interested also.

Third guy: I'll take it all, I can be there this afternoon, when can I come, my number is ***

Typically I would respond to the the first one who responded to my ad. This time I replied to the third guy cause he was the first to just say "I'll take it all, when can I come".
Did I do right? Or would you have responded to the first guy first.

Just curious
I always sell to the first person that puts the money in my hand, or pay pal account. So unless one of the other folks have paid in full, the parts are still for sale.
Also consider, just because the third guy is looking at the parts today, that does not mean he is going to buy them. That goes for all three, you have not yet made a deal.