Since when is a .26GHz increase and a minor bump in HD worth $300?
Wasted money. You don't have a 'mid-grade' model. You have a previous model. 2010s have a 320M which is the main deal. If you saved that $300 for the next gen model, that'd be a better choice.
Example:
Buy 2009 MBP13 low-end for $1200 (compared to $1500).
Sell 2009 MBP13 in 2010 for $900.
Buy 2010 MBP13 low-end for $1200.
Very true.
I do wish I had the 320M, but i'm definetly glad I spent the extra money and got the bigger hard drive and more memory, IMO it was worth it.
With the new one not having very much of a hard drive size increase, the sam rame and graphcs card, the lower grade might be more worth it, especially if the OP got an SSD with the extra money they saved.
I don't know about everyone on MacRumors Forums, but I tend to keep my computers for anywhere from 3-6 years. Paying the extra for the bigger hard drive and faster processor was worth it to me, just so I would be a little more "futureproof" was worth it.
If I planned on upgrading on the refresh, I would do exactly as you say, and buy the lower grade model, sell it, and then buy another lower grade on the refresh. However, as I don't do that, my solution works fine for me.
OP, you might want to take this into consideration. If you're planning on keeping your computer for 4 years, the upper model might be better for you, but if you want to keep it for a year, sell it and upgrade, then the lower one might be better.
All in all it really depends on what you want to do with it, how much you want to spend, and how long you are willing to keep the computer, as the upper models do not really have a higher resale value a year down the road if you wanted to upgrade.