Like anything its worth is whatever people are prepared to pay, I've seen them go for silly money and seen them go cheap. I paid well over the odds for a clapped out Cindercone because I was after one at the time. Intrinsic worth and personal value will always be different, I have had a Marin Rocky Ridge from new, the monetary value is probably about 150 quid on a good day but I'll not sell it because it's not about the money. Your Explosif is a fantastic bike and will benefit from having the crap ridden out of it.