The quality difference may be negligible depending on the individual bass and one's attention to detail but the sr1300 has the Atlas-4 5pc Wenge/Bubinga neck w/KTS™ TITANIUM rods and premium fret edge treatment. It comes with a gig bag too. The bridges are different as well.
SR1300 specs
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SR650 specs
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If that's the case, I'll probably just save up a bit and grab the premium. The sr700 above looked good, but factoring in the cost of getting nordy's and preamp to bring it on par with the premiums, and it ends up being around the same ballpark as a used sr1200-sr1400, depending on the quality and seller.