Reasonable wait time for response to buy/start trade?

I’m buying LiteCoin (any crypto currency) for my first time. I put in a request to buy LiteCoins from someone over 24 hours ago who listed on

What is a reasonable wait time to wait for a response to a trade? 24 hours? 2 days? 3 days? A week?

It’s been a week since I initiated the trade. The member I am trying to buy from was on 6 days ago and still not a peep.

Is this a good point in which to say “screw this” cancel the trade and try and buy from someone else?