If your really turned off by the Sigma's trigger or lack of safety then another good budget pistol to consider now is the Taurus 24/7. I have seen them regularly go for under $400 lately and to be honest IMO it is a better pistol.
My step sister's boyfriend bought one in .40 s&w a few weeks ago and I shot it last weekend. I think he said he got it for $360 from Bass Pro I believe. It was freezing cold out so we didn't go to the range and the only targets we had on hand was some empty 20oz coke bottles. I placed them (threw hard) off the back porch and loaded it up with some hornady ammo.
I was pretty surprised how nice the DA/SA trigger felt from the factory. No creep and it was pretty crisp, I mean we are not talking glass rod or anything but not bad almost comparable to my Sig p226 considering it was new and not broken in at all. At about 15 yds two hands with no rest, five bottles, five shots, five hits, not too bad. I fired the next ten as fast as I could get the front sight to settle on target and hit probably seven times out of the ten shots.
So while I still think the Sigma is a good deal for a cheap reliable pistol if your willing to tinker with it, especially at $250 with four mags when I bought mine, I think the 24/7 is really hard to beat at around $350-$375. To me the grip felt nice and comfortable, the finish was nice, the sights are way better (Heine's or Novak's) compared to the Sigma's basic plastic combat ramped rear and melted on front, I personally like having the extra safety for carry, and the trigger isn't even in the same ballpark. It also seemed to handle the .40's snappy recoil well too and I was fast back on target with it. We shot four 15 round magazines through it without a hicup and like I said it was the first time it was fired and he hadn't even cleaned the factory crap out of it. When we was done I took it down to clean and that was simple too.
Here is a link to Bud's, I was looking this morning and they are having a 24/7 super sale or something. I don't know if this has been going on for a while or not but it seems like their prices are pretty comparable to others I've seen locally.
http://www.budsgunshop.com/catalog/index.php/cPath/21_50_881