First off, I'm new here, Hi. I've posted a few things in the general forums, and after getting my A300K Don recommended hitting up this forum. Two days after buying the camera and I have a ton of questions, but I'll start with this one.

I have the kit lens and the Sony 75-300mm. I am pretty happy with these to have something to start with, but I would love to get something better for low light. From what I know so far that means a bigger aperature. When I was looking at cameras a lot of people recommended the Nikon or Canon "thrifty/nifty fifty" lens. 50mm f/1.8. I haven't seen anything newer for Sony that seems to be this kind of deal, but looking around ebay I saw a few large aperature 50mm. Some of them were from the Maxxim line, which I am pretty sure fits, but many were from the older non-AF lines. The only Sony I saw was the f/1.4, for $350. My wife isn't going to let me spend any amount of money any time soon on this, but I was thinking some of those older manual focus lenses might be a good (very) cheap way to get some new possibilties. Are those going to be compatible with my alpha, or is there a cut off for lens compatibility?

Beyond that, any other cheap lens recommendations for low light. Prime or zoom. I hope to get that widely loved Tamron f/2.8 sometime down the road, but it may be a while.