First off, welcome to the Forum.
I don't know about rare - but a 788 in .30-30 isn't real common just because of the cartridge. They produced plenty of them in other more common hunting calibers ( .243, .22-250, .308 ).
I think the thing that makes this weapon a bit better than the 700 is the fact that it has a short 60 degree bolt throw because of the 9 locking lugs. That makes it a stronger action and better for inherent accuracy.
If you like the gun, it doesn't sound like a bad price, but if you aren't dying for the caliber, I don't think you are going to find a market where you could buy this and turn around to double your money.
Your Mileage May Vary - Some of the Remington guys should be along shortly to give to the real story.