Runescape is a great MMORPG for those with a small budget.
You can play the game for free and while that should keep you busy for a while, the real fun happens when you become a member, which for $5 a month (more or less depending on your payment method), is a not a bad deal. Members get access to more than double the area and features on Runescape.
As far as graphics go, they aren't very good but this is understandable for a browser-based game. The music has a few decent moments but for the most part, its annoying and you'll most likely turn it off. Same goes for the sound effects, which are basically beeps and are sometimes unrecognizable,(sometimes I can't tell whether a sound is a bird or what).
Despite these flaws, for the low price and low system requirements, Runescape is a game easily accesible to many and is quite a fun game if you have the patience and time which you need for most MMORPGs.