Looks like a good price - is that $77 including all the ebay "surcharges"? - and you got the "X" not the "XP" (Plastic) w/ 2 chargers -- that package seems to fall right about $100 from net shops - so you saved $23 or a bit more since online shops will charge $4.60 to ship.
Streamlight definitely gives you more bang for the buck over surefire - and the 20X is a very versitile platform since you can put the 35's bulb in it and get more light output (with less runtime). I already owned a surefire 9N when I bought the SL-35 to get the longer runtime and higher light output. I still use both lights - it's better than trying to buy an "all-in-one" light that doesn't do anything well.