Yeah, my biggest regret was selling my C8 (8" SCT scope). I used it *all* the time as it was so portable. Used to chuck it in the car when we went camping with the kids, would carry it outside to look at anything, any time.
Now I have no real issues lifting a C14 up onto a GEM, however I found that even with a 12" scope I hardly ever go outside anymore, it was just that extra bit unweildy and took up more space in the car and was quite simply just more hassle.
If you only have $300 to spend, try to get something 2nd hand, it will usually come with advice and extras
But yeah, I would be physically lugging a sample around before buying and asking whether you are going to want to drag it outside each night. For me an 8" is the sweet spot, great views and still really portable. I'd love a 16" scope if I could set it up permanently, but if it has to be moved around... You know what they say, the best scope is the one you use the most.