DA 18-250 Question.

Ok as of now I have the DA 17-70, DA 55-300,Tamron 10-24 (so far seems pretty nice) and DA 35 2.8, now weight is starting to become a problem with my pentax sling bag i just bought (that is super nice BTW) but i was thinking of selling the 17-70 & 55-300 and order the DA 18-250 and maybe buy a couple more primes, would that be a better way to go as i think it would
Thanks;)
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300.