Inexperienced girlfriend trying to buy comics for collector boyfriend's birthday - need advice!

Hi! My boyfriend's birthday is coming up and he's recently gotten into a big collecting kick. I have access to his comic logging website and he's talked about it a lot so I know exactly which issues he wants to get, but I don't know where is the "right" place to get it or if there are fake ones that I should look out for.

Right now he's been trying to collect all the issues from #250 to the beginning of the Jim Lee Era of Uncanny X-Men (I don't even know if I'm wording this right). He's ordered some from eBay and comic book stores. It'd be kind of hard for me to get to a comic book store since I don't drive, so is eBay the best place for me to look or are there some other places that can help me get my footing? Are there places I should avoid? Is there a way to identify maybe fake issues on eBay? Would appreciate some advice!

Thanks!