I bought one last year on sale and used it all summer.  I like it, but it's my first yak.  The only issue is it seems slow and tough to paddle.  Are other 12' yaks in this price range also such a work out or is it just this model?

I have a perception pescador 12 and it is a breeze to paddle. Also paddled a coosa which is wider than the pescador and it felt much more sluggish. Hull design, lenght and width play a big part in how fast you are going the be able to paddle and how easy it is. You are going to find that speed is typically going to sacrifice stability in kayaks.

you can buy qua;ity used yaks from name brand makers for $500-700 used. They will come with extras like a good paddle, PFD, rod holders, FF, etc in some cases. Ive seen them as low as $350 here.

The hull features that tend to make a boat more stable (wide, flat beam with pontoon shapes underneath) also make those same hulls somewhat sluggish in the water. 

 

Everything's a trade-off...  

 

FWIW, look for any local kayak/canoe shops and call for demo days.  Most have a day (or more) at local bodies of water where you can get your butt wet in a wide variety of boats.  Get out and paddle some competitive boats and see what you still like/don't like about the yak you have.  In the end, only you can decide what suits you, your style of paddlin', and your budget.  A test drive here or there might be helpful.