tl;dr: If money is a limiting factor, I will buy you a copy of lipu pu. DM me on Discord.
lipu pu is a great learning resource and seminal document of toki pona, but it's the only one that costs money, and for good reason: jan Sonja (who deserves our support for the work she does for the toki pona community) needs to eat, and we live, quite unfortunately, in a capitalist world.
If you'd like to own a copy of lipu pu, but you are or feel limited by money in being able to buy a copy, I will buy you a copy. You don't need to explain or justify yourself to me in any way, and you certainly don't need to feel bad or demonstrate feeling bad about asking. I am fortunate to have enough money that I can budget some of it to support the toki pona community in this way, and am happy to benefit you (and jan Sonja) by doing so. If you'd like me to buy you a copy of lipu pu, please DM me on Discord. The logistics will presumably vary by jurisdiction, but easiest is generally if I can Venmo/PayPal/etc. you the money for it.
I use a token bucket approach to budgeting for this. Currently the bucket has 12 copies of lipu pu in it. More tokens will be added over time.