yes, you have taxes from the custom. Guitar shelter's shipping charge is not high ( well, much cheaper than some other japanese shops) but it depends of the guitar you're buying, if it's a LP junior with soft case, it won't be the same than for a Gretsch with hardcase so it's difficult to give you more infos.
They're reliable, shipping is fast. If I had to choose between guitar shelter and an ebay dealer I would go for G.S. they know the stuff they're selling, they don't lie about the items, they put the right price on the stuff they're selling, etc... It's safe, sure and less expensive.
To my point of view, I would go for private sellers only if their higher price is due to their high nowledge of the stuff they're selling. ( like villager for exemple).