I work with printers all the time in my day job. I choose printers depending on what the situation.
If I need a large number of professional prints and time in not an issue, I go to
printplace.com. It takes longer because they are printed in Texas and then shipped to me. I have found that online print ordering is cost effective. I also like using them when it is something out of the usual.
If I need a quick turnaround I use a local printer at
Sir Speedy. My local guy has good pricing and you do start a relationship with local owners. This really helps when you need help with printing questions.
The only time I use Kinkos is if I need to get something done very quickly and price is not a concern. They are great to use when you need something printed and picked up in another city. This happens when we have trade shows in other cities and printing has to be done NOW. I would have to say they are not cost effective. When I see the cost, compared to other vendors, I am always shocked.