I've had ~700 sales since I started about 1.5 years ago and now Etsy pays the mortgage. I don't usually renew as a means of promotion. When an item sells it renews itself, so that puts it back on top, but I don't do that as a practice.
Having 100+ items in my shop has been a huge help, as has labeling things accurately to my target market. I've also focused on just selling those items that are more unique. I started selling dresses in fun colors, but the market was WAY too saturated. By looking at my shop stats I noticed that people were looking for white dresses and jon jon's, mostly for weddings, photos and celebrations. That is now 70-85% of my business most of the year.
I'd say focus on building a bigger shop or have multiple listings for the same/similar items as opposed to just renewing what you have.