I have bought there before, but check their feedback certainly. Also contact the seller and see how they interact. Some very reasonable prices/deals.
They typically will add 3% or so for credit cards and I saw one that added some amount for "Insurance". Shipping is typically stated on the page. You will need to agree receipt with a local FFL dealer and the cost here can vary between $30 and maybe $50 or more for local processing.
Unless you are lucky enough to be near USDS in Greenwood. $15 transfers!
or BZ in plainfield=$15 also!!