I have never kept track of the hrs because it might make me ill LOL I have spent up to a week finishing a kit - this includes doing previews/ads/descriptions, double checking elements, and taking kit on test drive

I only work when ds is napping or down for the night so hrs may vary.(I surf on laptop the rest of the time

Some kits are super easy and finish quickly so it just depends.
But it sounds like you are running out of RAM. I worked well on less than 1 gig but anything lower than 700 might not be enough.