I don't know anything specifically about eShares, but I do know this: in regular startups, the purpose of a 409a is to set the strike price of the options for common equity that you give to employees. Companies have an interest to have that number come out as low as possible so that employees can afford the options and don't get snagged by AMT.
Since that's the interest, a lot of firms that provide 409a valuations have learned to generate the lowest defensible share price. That might not align with your current objective, since you aren't trying to generate the lowest possible price, but a (presumably) fair price that both you and your key hire would agree to. This would be something that would be worth discussing with both the 409a valuation company and your key hire
Carta charges $2k for up to ten people for one year. That includes the 409a valuation plus a bunch of other reporting and management features. Does that sound like a good price to you?
Since that's the interest, a lot of firms that provide 409a valuations have learned to generate the lowest defensible share price. That might not align with your current objective, since you aren't trying to generate the lowest possible price, but a (presumably) fair price that both you and your key hire would agree to. This would be something that would be worth discussing with both the 409a valuation company and your key hire