Best solution to convert a 12 ink cartridge roland printer

Hello guys! I need some help thinking so you maybe could help me out. The thing is that i own an XJ-740 with 12 ink cartrigde eco sol max, so you can imagine the cost . I've looked differents "solutions" to this issue. The first solution i been thinking off is to buy third party ink cartridges otherwise is imposible compete against another printing companies.
The second solution is to convert from cartrigde to bulk, but i've heard is expensive. I'm right? Does anyone knows if its dificult to install? Would be nice if you have some installation guides or videos you can recomend
And the third solution i been thinking is to buy refillable cartridges. Does anyone know how its works? Do i need to convert to bulk if i want to use them? Or its only to plug in and refill?

Thanks for answering guys! I appreciate it <3