Lulu often has coupons (check here & here) so you can get your RPG fix a bit cheaper than usual. But what to buy? Here’s a list of things that I like.
I recommend changing the LULU storefront to the US store (for USD) or the Ireland store (for €) because they have the best coupons.
I’m listing the paper book option, but sometimes there are ebooks or hardcovers available as well.

If you are interested in some more lists, check out Martin Ralya’s recommendations (OSR and other stuff), Tim Short’s list (OSR) or Wayne Rossi’s page (OSR).

Bookkeeping Notes: Some of the links below are affiliate links. If you choose to make a purchase, I will earn a commission. This commission comes at no extra cost to you. I recommend the products because I found them enjoyable, not because of the small commissions I make if you decide to buy something. But please do not spend any money on these products unless you feel you need them.

Lulu Non-OSR

Lulu OSR