I see no disadvantage if you are a smart shopper. Many other reputable firms. JM Bullion is another great firm. Go to their web sites. Compare all cost. Don't pay any sales tax. Free shipping? Storage or physical delivery. Buy back policy
I believe that local coin dealers have to charge a sales tax. That in my opinion is the major advantage of buying from the major firms like Rosland, JM Bullion, Goldline or Blanchard. Compare all cost. Be aware of all cost. All info is readily available. Shop smart, these firms are not out to rip you off.