At least in Belgium (where there are several generics available besides the 'brand' Truvada), my out of pocket cost is 5 euro for a month's supply.

If you take PrEP periodically (2+1+1) that will even last you a lot longer (depending on the frequency of course). I am very glad PrEP exists, and already optimistic about its impact in reducing transmissions. But if we can replace this with a one-shot vaccine, that would be groundbreaking.