I've cruised in inside cabins, "outside" cabins, balcony cabins...and we're going to Alaska next month in a couple of Sky Suites...
Frankly, it makes little difference to me...just get me on the ship...You get the same food, the same entertyainment and the same ports...
And, it's really not like having "a house without windows" at all...For most folks, you are only in your room to sleep and change clothes...At nightm the view out of the window is generally blackness...The one major difference withg an inside is you don't know when morning is...so you learn to depend on wake-up calls...
The ordinary inside and outside cabins are IDENTICAL in size and configuration...There is not much difference until you get to a "balcony"...There you have a similar cabin but a little extra usable space outside...so, depending on your lifestyle (say, you enjoy a drink before dinner while your spouse is getting dressed or you like room service breakfast and it's nice to eat it out on the balcony), the balcony really is a step up...But, of course, THAT upgrade...or the upgrade to a Suite...is a lot costlier...
But, if money is any kind of issue, you're not getting all that much from just a small window...I'd save the money and use it on your bar bill, a shore excursion or a nice souvenir from one of the ports...Or apply it to your NEXT cruise...Save $300 bucks for a few straight cruises and it's like getting a free cruise...