help please :P

hi i was wondering if someone could help me please. i was recently gifted a bottle of st magdalenes / waterloo street 20 year old limited edition single malt whiskey. i plan on keeping it for my daughter and was wondering what the value of this bottle is and wether it is worth keeping for her in the future. all i know is that its in mint condition and is a 396 edition. it comes in its original box with an accompanying letter describing a little bit about the whiskey and its corresponding number / issue. any help would be appreciated. all the info i have been able to find online is from the link below, i dont feel this is a true valuation though as there isnt anything too compare it to.thanks

thewhiskyexchange.com/P-8619.aspx

[Son-o'-the-Sod(?)]

I'm wondering why you question the valuation?

i only question the valuation because i received it for free and because i could only find 1 example of it for sale. my worry was that the whiskey itself wasnt valuable but the fact it was a low issue and had other factors gave it value.I actually thought it would be worth no where near that amount and if i thought i could sell it for half of that i would.im not a whiskey drinker but have a nice dalwhinnie 36 year old single malt i keep for special occasions.it would be a waste if i was to also open this bottle as i dont have the palette for it to be honest.