OK people, read the Vermont DMV's instructions.
There are three rules in play here: bikes under 300cc are never titled, nothing 15+ years old is titled, but bikes over 500cc require a VIN verification even if they're not titled.
This leads to four possibilities:
1) bike under 300cc: not titled in VT, regardless of age
. No VIN verification required, no title required. Send bill of sale, complete application and fees, get registration and license plate. An EX250 fits into this category regardless of age.
You are reading this correctly: even a brand new EX250/CRF250L/etc. in Vermont is not titled.
2) bike >300cc but <500cc and
15+ years old: no title, no VIN verification. Send bill of sale, complete application and fees, get registration and license plate. This small category would apply to a 1976 KZ400, for example.
3) bike >500cc and
15+ years old: no title, but VIN verification required. Send bill of sale, complete application, VIN verification form and fees, get registration and license plate. Exception: if you have a VT registration for this bike in any previous owner's name, the VIN verification is waived. For this purpose, the previous registration can be expired. You do have to submit a copy in lieu of the VIN verification. A 1981 CB750 fits into this category.
4) bike >300cc and
0-14 years old: these bikes are titled in Vermont.
You'll need a title to get anywhere if your machine fits this category, and if you have the title, you can probably go through your own state. Should you choose to title in Vermont anyway, you'll need a VIN verification in addition to the properly endorsed title from the seller.
Just in case anyone is wondering, for cars there are only two possibilities: either it's 15+ years old or it's not. Cars 15+ years old never
need a VIN verification; that special requirement is only for motorcycles. Cars 0-14 years old are titled.
Also worth noting is that Vermont has started to bust people trying to register dirt bikes. If your bike was not originally manufactured for street use, prepare to be asked to show that the bike is street legal. They go by the VIN, so factory dualsports won't be an issue since they've always been street bikes in the eyes of USDOT.
Sales tax is based on the purchase price or NADA's New England price guide, whichever is higher. DMV will give book values over the phone. In my experience, whether they check the book value is hit or miss; they seem more likely to check on mailed applications than ones submitted in person. If you want to fight over the value, the appraisal has to be done by a Vermont licensed dealer, so if you're not close to Vermont, you're essentially left to pay up or shut up. Per ride4321 below, the minimum value for tax purposes is now $500, so you pay tax on $500 ($30 at the current 6%) if you paid less for the bike.
Vermont does not
suspend registrations for lack of an inspection certificate like Mass (and possibly NY?) does. If you ride in Vermont on Vermont plates without an inspection sticker, you can be cited. If you ride in a state without safety inspection, you're good to go. If you ride in a state other than Vermont that does have safety inspection, check your local laws. I believe NH and Maine have specific reciprocity with Vermont and could (in theory) cite you; in other states I have no idea--we don't have that shit out West and I don't live in Mass anymore.
This is between you, your insurance company, and any cop that happens to stop you. Vermont does not
use an insurance database to suspend registrations of uninsured vehicles like a substantial number of states do. Riding without insurance is illegal in 45+ states (including Vermont), though, so going without is an extremely bad idea. Get insurance. Your insurance company doesn't care where the bike is tagged.
Over and above all of this, it's generally illegal for a resident of a state to register his vehicles elsewhere. If you get stopped by your local gendarme with Vermont plates and can't talk your way out of the ticket for not registering your bike in your state, don't come crying to me about it. Check those light bulbs, people!
ETA: if you live close enough to Vermont to visit one of their DMV offices, just do that. They can do VIN checks there, and they hand plates over the counter. I've done two bikes, one by mail and one in person. I also registered a car by mail and then transferred those plates in person to a different car after some stupid Masshole flattened the first car. Every one of those vehicles was later registered in another state (Colorado for both bikes and the flattened car, Mass for the replacement car) with minimal hassle.