For me it's not the cost. I have money to p*ss away on my baby. The reason I don't want one now is the technology is still young. When it matures a bit then I'll reconsider.
Basically what i do. Well OS/Programs go on SSD. The programs never get changed once installed so all is well. Games/downloads etc all go on my HDD.
If the OP has the cash to splash on a SSD then it really is a no-brainer these day's. SSD's have come on in leaps and bounds in the past few months. Plus even the basic one's come with something like 3 years warranty and higher spec one's such as Samsung Pro's come with 5 years.
To be honest as well on speeds, unless the person in question is a major benchmark fanatic then there is really not much difference between most SSD's nowadays.