I'm not a pro mechanic, mainly just do fabrication work out of my garage and out of the guy that I work withs garage. I still prefer to have the best tools I can. If I was a pro wrench I would buy all snap on because while there may be cheaper alternatives for screwdrivers from one place, wrenches from another, sockets from somewhere else...I can buy snap on and know that whatever I get will be a high quality product. And I won't have to search all over and do a crapton of research to find a deal (time IS money).
I think Snap On is great because in most cases you can count on them to be high quality, its a 1 stop shop for your tool needs, great customer service & warranty, etc. Spending even a few hours online for a better deal on a set of comparable quality screwdrivers would pay for the snap on screwdrivers had you spent those few hours actually working.
I do find myself doing this, over researching every little thing I buy on the web. I've spent 2-3 evenings searching for the best buffer, what people say about them on forums, reviews, etc. Had I spent those hours making money and just bought what I knew was high quality I would have probably come out ahead. A lot of these guys don't want to spend all of their off hours investigating tool options either. They buy what is good and move on.
As for owing your employer and it being wrong to do side work, give me a break. Yes doing side work at work or on their time is wrong. Having your own clients / friends that pay you to do work on a Saturday is your own business.
Way too many employers act like they deserve one-way loyalty. Sorry but paying someone a crappy wage doesn't mean they owe you their lives. It seems many businesses think the best way to make a profit is to send guys home every time there is even the mildest slowdown of paying work to keep up efficiency, and then turn around and demand 110% effort and perfect attendance. It is a 2 way street. If you pay people fairly, treat them like human beings that have needs and families, and at least fake gratitude for doing a good job, those people will do better / more work for you.
If you have a guy that can diagnose any problem, is willing to help the other workers when they have trouble, is willing to do what you need him to do at any time, then it is probably a good idea to pay him well and NOT nitpick him for small percieved problems such as taking 32 minute lunches or going to the bathroom "too much", or him asking to come in early so he can leave early to attend some function of his kid's.