New players don't have the Presence bonus for their companions, so it will be more challenging.
I'd suggest upgrading every so often, especially if you get to a story quest fight that's tough to beat.
My first time through (scoundrel- healer), I recall there was a fight on Tatooine I had huge problems beating.
In fact, many of the boss fights for that toon were tough, all because of a lack of Presence.
So if you're going to be frugal with gear, stop by the companion gift vendor.