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

You're the seller. You can sell to whomever you damn well want to. You did fine.