I have made a ton of mistakes when it comes to buying domain names, and hopefully you can benefit from my experiences -
First - you don’t have to make a loser’s decision here. Go for both. Pick a brandable domain name that is also keyword rich. So if i were looking for a domain name for a shopping website I wouldn’t torture myself over whether shop-guide.com is better than spendr.com. I’d simply go for a name like shopfish.com or shopon.com which have the keyword(s) i want and also is brandable and memorable.