I got into Batman just watching TAS and the movies; same for Superman, Spiderman, The Avengers, etc. As someone who never read the comics for these guys, if Arrow stands out on its own as a great show, then I will enjoy it.
And I would check eBay regardless. The Target sale on Hannibal and such expired yesterday, according to the tag. But I saw DVD copies of Arrow and Hannibal Season 1 on eBay for as low as $10 when I checked yesterday (not new, mind you, if you care for that stuff). I got a lot of my DVDs recently on eBay. $28 for Downton Abbey Seasons 1-3, $40 for Justified Seasons 1-4, $45 for Sons of Anarchy Seasons 1-5...I also saw Walking Dead Seasons 1-3 on DVD for $25-30 (I bought the Season 1 LE and Season 2 on Blu-Ray stupidly from Best Buy for $40, but the LE was worth it and since they had Season 2 for the same price...heck with it), Tudors Complete Box Set for $30-40, Borgias Complete Series for $25-30, but ran out of cash for them...hopefully, if they are still on sale when I get some more, I'll go for them.
You can get some good DVD deals on eBay for TV if you keep an eye out. I'm preparing to get a DVD binder to load up with my disks and put the cases into storage.