Going back to the trial data comparing these two drugs it does appear that there is a small safety difference. Lucentis (the expensive one) was slightly safer. (See http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(13)61501-9/fulltext#fig5 – Figure 5. The safety difference may not be enough to justify the cost, but it seems reasonable for ethical doctors to recommend the safer option for their patient regardless of how much they get reimbursed. I don’t think you can assume they are choosing it just for the money. If, as a patient, I were given a choice between the two I would choose Lucentis, because I would not give up the small safety benefit just to save my insurance company some cash.