Ive been mostly buying my blu-rays off amazon. Half the $ amount required for free shipping, and usually much lower prices than rightstuf. Another good thing is you can save items to your wishlist, and it'll show when the price drops from the original (original from when you added it, instead of the suggested price)
And yeah, I have problems dropping shows. I always feel obliged to finish it.
I also have a problem with not dropping shows I'm not enjoying. Red Data Girl bored the hell out of me but I was already halfway through so I thought I might as well finish it. Same with Nyaruko, Valvrave (not so much boring but just not very good IMO), Dansai Bunri, etc. I suck at dropping things once I'm 3+ episodes in. Probably a minor case of OCD.
I mostly go by episode reviews and first impressions posts by various anime blogs I enjoy to weed out the bad stuff, I'm just typically right when something looks like I won't enjoy it. Most of the romcom and moe stuff is typically passed over, just because so few are worthwhile nowadays. When one's great I'll just wait for other people to inform me so I don't have to test them all out myself.
http://psgels.net/ is the guy I like the most, his tastes always seem to be very similar to mine and he'll watch the first episode or two of every show each season and give some first impressions.