I don’t have a local train store, so, by default, everything I buy these days comes via mail order. That includes Z scale, Marklin HO, O gauge, On30, Standard Gauge, and Large Scale stuff. I’ve had great success in buying from select dealers I know and trust based on prior experience in dealing with these folks.
With one exception, I have never received a train by mail order that was damaged in shipping. That one exception was a Marklin MAXI locomotive, and Marklin (not the dealer) sent me a brand new one and just asked that I use the same shipping box (in which the new one was received) to return the damaged item. Other than that, I’ve been lucky enough to find good dealers in various parts of the country who take my order properly; sell at good prices; pack the items carefully; ship promptly, and who appear to be generally held in high regard by most in the hobby community (or, at least, those whose opinions I respect and value).
If I had a decent local dealer, I surely would support him, even it an item cost a bit more. In other areas where I previously lived–Baltimore, Milwaukee, and Norfolk, for example–I always gave my business to local dealers first, assuming they had what I was looking for. I like keeping my money in the local economy, and I like supporting local small business. Besides that, it’s nice to have a friend who sells trains, and to have a shop to hang-out at and meet other hobbyists.
The mail order dealers I deal with regularly are Charles Ro (Lionel), Trainworld (Bachmann On30), Ready-to-Roll (MTH Standard Gauge), Modelbahn Ott (Marklin HO and Z), Davis Trains (K-Line, Lionel, MTH), Star Hobby (Large Scale), Watts Train Shop (LGB), St. Aubin Hobbies (Large Scale and On30), Ma & Pa (Williams), Nassau Hobbies (Lionel), Sommerfeld Trains (Lionel, MTH), JusTrains (Williams, MTH), Trans-Global Hobbies (Marklin Z), and Micro Macro Mundo (Marklin Z and MAXI).
There are plenty of other good dealers around, as well, but these are the ones I