Criticing Others

Is it legal to name other people's websites and openly criticise them(with total and complete justification and back up of our comments of course)

Basically, we sell electrical equipment and phones in the brick and mortar world and have a private associates website which is very small.

Our site is not on the WWW because it's where our real world customers and friends hang out; sorta like a hang out jaunt.

Anyway, we see other companies charging as much as 5 times as the exact brand phones that we offer and stuff so my question is: can we mention in our website and make public certain comments like

"www.soandso.com is charging $79 for electrical wiring whilst we are doing the exact same thing for only $49"

"why are you paying www.soandso.com $93 for the Putra phone when we are offering the Putra Semi(which is even better than Putra) phone for $88 and the Putra phone(what he is offering) for $79"

"why are you being fooled into handing $198 for the complete internal wiring to www.soandso.com when we are oferin gthe exactly same service for $159"

I look forward to a comment on this and Thanks