Given that the XPS M1530 were designed as mid range gaming laptops when they were made I'd say if it still plays the games or does what you want it to why upgrade to a new machine and spend even more money.
The SSD is well worth the money for the speed you'll get and if you ever do upgrade to a newer laptop you could easily make the SSD over, replace it with another standard HDD and sell the XPS that way to recoup some of the upgrade cost. Also SSD is the best bang for the buck right now with HDD prices being crazy from the Thailand floods earlier this year.As for the ram upgrade if you only have 2GB I would higly recommend going to 4 or even 8 if your budget allows it. The speed improvement you'd see with that + the SSD would make it feel like a whole new machine.
for both upgrades you could be at or under the $200 mark which is about 1/4 the cost of a newer entry level machine with a dedicated graphics card.
With those points covered though I do agree with frozenland that if the notebook isn't quite performing up to snuff now than it's most likely too old for an SSD and RAM upgrade to save it in which case I would start looking at a new machine to replace it.