okay, i will be helpful.heres my advice:
1. go to a shop.2. talk to a boot fitter.3. get sized.4. do not buy boots online, especially used ones UNLESS you've tried on the EXACT year/model of boot on in a store and it was suggested by the fitter.
its just not a good idea to get something as important as boots online without any prior knowledge of them. you will probably end up spending more, but in the end it will be worth it to have proper fitting boots.