Definitely recommend going the refurbished route if you can.
The current MacBook Pro I have (15" 2.2ghz C2D SR) I purchased in late october 2007 refurbished. almost 3 years later, I have had no issues with it and at the time, I remember saving $200 off the price versus new (would have only saved $100 w/ my educational discount) - and then on top of that, I was able to get a $100 rebate because I went through a 3rd party making the price even cheaper. But, I don't think those kinds of additional rebates can be done anymore - the person I went through (found on macrumors) said they're not involved with that anymore.
I bought a mac mini refurbished earlier this year before the upgrade, no problems there either but not really using it a terrible amount. Usualy for something like a mac mini, I'd try to go the craigslist route.
I can see that the resale value is affected because you don't have the original packaging (which is true whether or not the item is refurbished). Are you saying that other than that, being refurbished lowers its resale value?
I wouldn't worry about the resale value because the savings up front more important. A few years from now when you want to sell, I think having hte refurbished box still shouldn't impact much.
I'm actually looking to replace my MacBook Pro now because I want to sell before the applecare is up. I only want a 15" and am trying to get to the bottom of a) if the jump to i7 from i5 and b) the jump from NVIDIA GeForce GT 330M w/ 512MB is better than 256mb is worth the extra $340ish price difference in refurb costs ($1529 to $1869). Or, on top of that, if the hi res screen is worth it which would take me to $1999 in refurb costs
I don't care about the increase in hard drive space really. 320gb should be fine for the immediate future. I have a 500gb external western digital My Passport studio hard drive and if this hard drive can fit in the MacBook Pro, I could just take this apart and throw it in there one day. That's what I did w/ my older 320gb western digital hard drive when the enclosure got messed up, I just took out the (I think) 80gb hard drive and put that in there instead.
I also one day want to put an SSD in there too and take out the superdrive.