Simply be truthful to your client, don’t cheat him.
If you are late to respond, then tell him as follows:
In fact an in depth review takes time so that’s why i couldn’t respond you earlier. I hope you understand. But don’t worry, i am active and will deliver the order within promised number of days once you will order.
You would get a reply like this or even better:
I like that you actually take the time to look into things properly. I’ll never work with someone who comes up with a price for something like this in 5 minutes.
P.S. Those bidders should think about it who remain very active in bidding and at the end they just got exhaust.
Last updated: August 23, 2015