closed baseinvest.com - quick advice appreciated

[Poohnix]

I registered baseinvest.com a few months ago and haven't thought much about it since, but now someone is showing an interest for it and has been calling several times the last few days and left messages at my voicemail.
I've been traveling and haven't had time to call back yet, but would like some input about what price range I could possibly ask for this domain.
It doesn't have any history, registered and parked a few months ago, but the interested party appears to be an end user.

Any feedback is appreciated. :yes:

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