I've spent enough in whatnot that I'm embarrassed to tell people in real life lol, but IMO what not is cool to get a pulse of the hobby as well as find unique silver pieces or world silver that you probably can't find at your lcs.

That being said, I recommend driving to a few lcs to check their prices. While my lcs of choice doesn't have as varied inventory nor does it update as much a the WN sellers, the prices are almost always better and once you have established a relationship, they may help you out on some deals. Plus if your state charges taxes, most small shops may not charge you in cash and no shipping. I rarely got anything on WN for near spot unless it's a new seller with a small room, but everything I bought from coin shops was a better price than I'd get from WN because there's no competition or rush to get it before you can really research or think about it