There are all kinds of free thermal imaging courses online to help you decide what camera to buy and what camera to use for what purpose.
Your question is to vague and would take a few weeks to answer. Other than putting two equipment datasheets side-by-side and comparing, there is not much else to say.
We don’t know how you will use the camera and a lot of the bells and whistles that you get with cameras will make your job “feasible”. If you do 700 electrical panels on one job, screw up the identification of just one of them and you have a bad week getting things straightened out!
If you decide that you want to do 15 different infrared applications (like are posted on the Internet all over the place) you must realize that one camera was designed for one specific purpose. If you have the wrong camera, you can’t do the job, plain and simple.
If the client requires you to use a specific camera and you bought the cheap version that doesn’t meet the grade, what you going to do?
If you’re going to just use your camera for home inspections, the client does not have that much of an “at risk liability” to justify paying for the camera in my opinion.
This opinion is supported by all the cameras on eBay.
But to utilize a low-end camera for building applications is unwise because it requires a higher end camera to get the job done. A lot of folks seem to think that a camera is a camera, but an I3 is like driving in a snowstorm versus a sunny day!