With Ironworks and Augmented Shire being so insanely accessible at this point 50 and 60 should be easy levels to gear. I think leading up to 50 you're very safe using dungeon drops and NQ vendor whites and if you upgrade to hq white gear at 66 (usually pretty affordable from the mb, I've done it for every class I've taken to 70) you can make it to 70 really comfortably.

If someone isn't reasonably up to date on their gear it's their own fault and it can be a real detriment to the party, especially as a tank lacking armor or a healer with a poor weapon.