I started really getting into the lore with Ghosts of Onyx back in 2006. And yes, keeping up with the lore is definitely expensive. My plan of attack back when I needed to catch up was to ask for the older stuff as gifts on my birthday or the holidays. That way, I had the spare money on hand to buy any new lore content that came out. Of course, I didn't have the money to get the more periphery older items like encyclopedia or comics, so I held off on those until earlier this year when graduation gifts gave me the money needed to buy those. Now that I'm caught up though, it's super easy to just buy the latest thing. My recommendation if you want to get into the lore is to buy what's coming up and recently out, and then getting the older stuff as gifts. Of course, you may feel compelled to treat the novels as an entire series and tackle it at that angle, which is also a good way, it just might mean you won't be as up to date with the current lore depending on how you tackle it.