The store within E-Bay does work and displays all of their products properly. I have noticed this morning that the link I originally provided to the EBay store does not work when I am not logged in. Try searching for the seller ID nastjuschka06 under "Advanced Search - Find items by seller." or conversely, just search for "Sanka tomato seeds" (within EBay) to go to a first item. Once you locate an item, there is a link to their EBay store without a login.
As folks note, their own site
www.nikitovka.com does not function, but the setup and product counts are identical to the EBay store.
Concerns about using EBay? With Nikitoka you can only use PayPay with the inherent security built into their model & in addition, you will have 45 days to register a complaint if you have problems - lots of time to do germination tests if you are worried about old seeds.
rg