The Lansky Deluxe Five Stone Sharpening System is widely available on numerous sites, and has been around for quite some time.
The final delivered cost between Massdrop, and other sites is very similar, and the historical range has basically been in the low thirties to the mid forties for several years...
For example, the delivered cost from Massdrop is currently $36.49, and most individuals will not currently pay any sales tax when purchasing on Massdrop.
Amazon offers the same product for $33.19 delivered, plus sales tax if applicable, which in my area is 6.5% additional, so $35.35 total, which is still a bit better than Massdrop, and you won;t have to wait very long to receive it. If you have Prime, you will receive it in two days with second day free shipping.
Walmart has the Lanky system for the same price ($33.19) as Amazon, but you must spend at least $35 to get free shipping, so perhaps you can add a small add on product to your order, or simply just drive to the nearest Walmart, and pick up the Lansky system for no additional cost, except again I have to pay the sales tax of 6.5% in my area, so basically the exact same price as Amazon on 5/25/2018.
In my case, I have numerous Walmart stores withing a few minutes drive of my home, so $35.35 which includes the sales tax, would be the best deal, at least for me, and I can get my $20 oil change, and pick up a gallon of milk, and some bananas while I am there. LOL
You can also find the Lansky Deluxe Five Stone Sharpening System on EBAY for $35.49, (delivered) with free shipping and you probably will pay no sales tax, so EBAY looks like the best deal if you don't want to leave your house.
I'd love to see the Lansky Deluxe Five Stone Sharpening System at a sub $30 price delivered, say like $25.00, but so far no luck.