"from" is a warning signal; "from £5" can be (and often is) £10. Just and Only are generally fine. But you should always check what price other sellers are operating, to be on the safe side.
From, just and only are not key words unless they have another word attached.
From -- price is not good as it indicates the price is likely to be higher
Just - what? Just on the market, just issued ..? not a priority for me
Only - suggests desperation, only 4 left, only this price until Monday
I worry about "guarantee", though, unless it's very clear and unambiguous, it means you're going to have to plough through a lot of fine print to see whether it really covers anything that might happen.
Not really attracted by "new"; I don't want to be a guinea pig and I'm not into beta versions. I'll start thinking about buying something when it's a few months old and I've read the reviews.