This is a repair I did recently. It was a rental property and the landlord instructed me to use the brand new off cut to repair this damage.
Ok, so the repair is visible, but only because of the colour variation. The joins are tight and uniform.
*************************************************
Getting back to the original question, in any service based business, once the initial service has covered your costs, then from there on, you should be simply working it out on time x your desired hourly rate. This doesn't mean you have to tell the client what you charge per hour, some people get funny with that (my Dr only charges $xx/hr) you can still per piece price it, just not as high. I aim for $135-160/hr for my first hour and $90-100/hr subsequent hours. Not cheap, but I'm efficient, and I save carpet. I assess each job before I take it on. Can I deliver a service that meets or exceds expectations before I commit.
I measure my jobs by a few factors.
1. will me repair work last as long as the remainder of the carpet?
2. would I be happy with that in my home?
3. can I leave my work invisible?
4. can I provide a service that is cost efficient?
The fist is a must meet criteria, otherwise I walk.
The other three are ideals that I strive for. But they don't always get met. Sometimes, you can't make your work invisible due to wear and or fade differences. Sometimes the client would prefer the original repaired because of the terms of their insurance policies so this is the better of the two options.
Two things that are paramount in personality for a good repair technician are:-
1. patience.
2. attention to detail/perfectionist.
If you can apply these few things I've listed here to your repair work, you will do well at it. Layers/installer generally HATE repair work. As a general rule. that comes about for two reasons, new goods are far more pliable and easier to work with but also they have been 'bred' with a contract mentality. As a result, they don't have the patience to sit there and get it right.
So, if you can portray yourself as a repair specialist, you will get a lot of referrals from the retailers and their layers.
Of course, you may simply want the skills to add on a service to your clientelle while in their home, BUT make sure that added service is not inferior to the level of service your client has come to expect with your cleaning. If the repairs are an ugly reminder of your work, they won't call you back for any of the work.
John