T&G floor decking-- southern yellow vs spruce/pine

[Erin]

so my local yard guy can get 2x6 spruce/pine T&G decking for 1000 more (for my whole order, of course) than menards' decking in a southern yellow pine.

now, I know syp tends to turn into bananas if it sits too long, but we're going to install almost immediately.  however, my local guy also said that because syp is a southern tree it'll shrink too much for our semi-arid part of the world.   
I must say, I've never heard that one before.  what say you guys?  and which direction do you think you'd go?  big box for $3500 or local for $4500?

[Bob S.]

I would buy a cutter head and make my floor out of re-clamed boards gleaned from free pallets and save about $4,000.00.                     

[Squirl]

That doesn't make a lot of sense, unless he is selling some wet southern yellow pine.

I've only heard it as across species, not location grown. 
http://www.woodbin.com/calcs/shrinkulator.htm

According to the shrinkulator, they are all close to the same percentage of shrinkage of around 7-7.5% between almost all varieties of pine and spruce.

[Erin]

This is structural, Bob.  It has to be 2x.

And yeah, Squirl, that's what I was thinking too.  Like I said, this was a new one on me.  In fact, I found it a little off-putting--like he was trying to BS me.      And that's swaying my opinion on whether to spend the extra $1000 to support a local business (and maybe have a slightly better product!) or save my pennies...


Not to mention, SYP is considerably harder than SPF.  Ie, better for a floor, I would think.