I've had this mental 'exercise' many times, about whether or not we should be carrying a spare.
Our 2012 Georgetown MH does not have a spare, which surprised me at first. Have thought about putting one on, but more I think about it, I have come to the conclusion that it is better without one. Here's why:
If I was to carry a spare and plan to change it myself in the event of a blowout, I'd need to buy, carry the following:
1. Spare tire itself plus rim for it, easily $500 or more
2. Portable impact or gear wrench strong enough to remove lugs, another $50-100
3. Appropriate rack/holder to mount spare underneath the MH (I aint wasting outside storage bin space), another $100
Sooo, thats a total of around $700 I'd have tied up in extra 'stuff', that there is a good chance would just waste away and never be used if no blowout occurs. All that, just to be prepared to change a tire myself in the off chance I have a blowout and Good Sam ERS could not help.
Oh, I will also have to spend another $400 every 7 years or so to replace that UNUSED spare once it ages (rots) out. That is the case, even if a blowout never happens. That, or just use one of old tires as the spare every time I purchase new tires. That means the spare is potentially 14 years old before it gets replaced, though (no thanks).
...And lets not forget the safety/health risks I'd be taking, if I ever try to change a tire myself by the side of the road. I ain't getting any younger, and these tires are NOT lightweight.
OR, I can keep all that $$ in the bank, not take the risk of an injury, and rely on Good Sam ERS and the roadside service they would send out to help in the case of a blowout.
I'm thinking, as rare as blowouts occur, I will be $$ ahead SIGNIFICANTLY in the long run, by just letting ERS handle any tire issues. Even if I one day get 'gouged' on a new tire somewhere in the middle of nowhere, compared to the cost of all I just mentioned + having to replace an (aged out) spare every so often, I'd still probably be $$ ahead overall.
Worst case, if blowout occurs and I pay an unusually high price for a replacement, I break even. Best (and much, much more likely) case, I'd be several hundred $$ ahead in the long run. And, thats without even getting into the risk of injury or health problems I'm avoiding, by not ever trying to change one of these tires by myself on the side of the road.
As for the difficulty of being stuck by the side of the road waiting for hours for roadside service: Not worried about that at all. I have pretty nice 'accommodations' to relax in while I wait in the MH. And, I have a towed vehicle I can unhitch and use to get everyone to a safer location if need be.
...Anyway, for those reasons, I chose not to carry a spare. Thats what I have Good Sam ERS for.