I prefer purchasing online as it's more economical...no tax and prices are generally much cheaper than LGS. ALthough supporting local shops is always a good gesture.
If it's a SW you are purchasing, you do not need to involve any LGS after purchase as SW will take care of any issue/complaints hassle free.
I have a FFL that does free transfer. You have to factor in tax, ffl fee, and shipping cost.
Whittaker Guns, Palmetto, Buds, Grabagun, and check slickguns for pricing.
Gunbuyer sometimes have great prices but their FFL process is a hassle with no FFL database.