Dilemma

Bought this Airfix kit from the local charity shop for a whole £4.99. Turns out it it a discontinued model has has quite a high value, significantly more than I paid for it.
Pondering whether to build it or list it on Ebay for £100. 
Who knew that there was such a thing as a collector of unbuilt model kits?  I have always regarded them as something to enjoy building which is what I will probably do.