I would not have registered it personally. What is the possible use for a plural of a type of bacteria in the .net extension. The .com is likely worth something due to type-ins.
A question I always try to ask myself before registering a name: What can this domain be used for? What kind of site, such that will attract visitors and serve a business?
I recommend getting a refund. EstiBot is overestimating this by about $40...
Good luck
Josh