Most basic shops are used to working on cars so the job "should" be faster than doing it yourself. You have shops that give other shops a bad name by dragging out the hours, doing sub par installs and over charging out the @ss for everything. If you only have those shops local to you then yeah doing it yourself, ordering online is the best way to go.
Its also unfair where there are legit shops that seriously know how to tune everything very well with professional equipment that get lumped in with these junk shops that are in it for a quick scam dollar. Once you actually talk to a few legit shops that actually price reasonably, know their **** and take pride in their work, your perspective of the "brick and mortar shop" will change.