I think this used to be a decent e-commerce plugin but not any longer. I wasted a week of my time trying to make 3.8.4 work, spent $$ on Gold Cart all to find out that there is NO documentation for the new version and what there is is completely wrong. The author chose to completely rewrite the product without telling anyone completely invalidating all of my work on the previous version with no notice.
Don't waste your time, money, or effort. Use something else.
(I've gone to Shopp if you're wondering)