If you have a blow-out while going down the road, the cost of a tire will be the least of your expenses. Repair of the fender plus all the damage related to damage from the tire banging around as you slow down will suck $$$ from your bank account. I've only seen two Alpine owners report on blow-outs on this forum and the repairs ran to the thousands of dollars. However, if carrying a spare will let you sleep easier then it a good sleep aid.
'99 Alpine Coach