It seems that people here are too dependent on them.
Depending on how you define "beat the game" cause there's no final objective in an MMORPG specially if it is incomplete ( or if it keeps on updating just for the sake of it ).
If you meant socializing with other players ( this is a(n) MMORPG anyway so playing the game with a mind set of doing everything by yourself defeats the purpose of "MMORPG" ), finishing quests, being rich, getting to max level or killing MVPs ( solo ) and such then the answer is YES you can . It is doable but it will take a lot of time and patience . The length to get to your goal varies on how much time you would put in the game ( if you're jobless, a student that's on vacation or you just don't have a life outside of RO then time won't be a big deal for you ) and last but not the least is your LUCK ( on monster drops, refines, enchants etc.. ).
You have to commit hard on this game to get to your personal "goal" with out using VIP benefits/ Shop items . In my opinion ( could be a fact too ) the VIP/ Shop items are there to keep the server up ( otherwise this game would've closed a long time ago ) and of course for people who wants to be rich and strong right away but doesn't have time to play all day...