Going rate for consultant in NY

Here's the situation I'm in NYC and had a contract installing a brand new system, server, cabling, workstations etc.  One of the main employees husbands is friends with the owner and now has asked me to setup his brand new building again server, most of the cabling was done by their workers but we may do some termination along with 7 workstations, router, switch etc.

I have no doubt that he knows the rate I charged the other company, is it wrong to charge a higher rates lets say $30 more an hour.  What reason do I provide if he questions why are you charging so much more or should I keep the rate the same as basically I got this through a referral.

Thanks

If the first company is in the same city area as the second one, you will have to justify, first to yourself, and second to the second company, why you are increasing rate.

Perhaps the new rate is your bench rate and the prior rate was to secure business at a discount.

I see the reasoning my wife who works for a law firm came up with the same explanation.  I'm just concerned my rates are too low.  I'm assuming the rates in NY vary from $150 to $200 is that correct, I'

This has been very helpful. Just curious do you charge the same rate to all your clients or sometimes do you have different rates depending on work and size of firm.

I charge the same rate for all clients. My rate is competitive and in my sphere of business, there is no reason for different rates. That does scare away some very tiny clients and that is fine with me.