I haven't gone to a con, but I know that it is quite a bit. One I almost went to would have taken 60 per pass alone, but it may differ elsewhere.

Take note that for everypony you bring with you will up the prices dramatically.

The hotel was free because my family travels like it's nobodies buisness, the passes were like 30 dollars and you can spend however the fuck much you want on merch. Around total it probably cost me 150 dollars. If you want to be financially secure then I'd recommend like 500$ depending on how long you plan to be at the con.