Best bang for buck under $500- Tam28-75 vs. Sig 17-70 vs. Canon 60 mm vs. Extender

I'm obsessing over what to add to my lens lineup.

- I shoot: Kids activities (kids sports and portraits mainly). Some travel and haven't done much Macro yet. I have shaky hands.

- Current Lens Lineup: Tokina 11-16mm, Canon 18-55 is, Sig 30 1.4, Canon 85 1.8, Canon 70-200 f/4 is, 430 EX flash

- I'm missing: Something longer than 200 mm; A nagging feeling that I need to upgrade the kit lens; Macro ability

What would you suggest for best bang for the buck? I have $400-$500 to spend.
1. Upgrade kit lens to a standard zoom that can also do macros (Between Tamon 28-75 and Sigma 17-70 2.8-4 OS ). Would the OS on the Sig benefit my shaky hands more than the better reported performance of the 28-75?

2. Get a macro that can also do portraits (Canon 60 mm )

3. Get Canon 1.4 extender

Given your current setup and what you're looking at, I would go for the Sigma 17-70. The way I personally see it, that 18-55 is the weakest point of what you have (not that it's a bad lens), and you would benefit the most from the extra reach, wider apertures, and OS.

The Canon 60mm and the 1.4 extender are really only good in limited situations.

I think the Sigma 17-70 would be the most usable (and most frequently used) option for you.

I just got Sigma 17-70 last week and I really like it so far. I haven't had much time to give it a good workout though.

I have two of the lenses you're considering. The Tamron is a terrific "people" lens, and is also very sharp. I use mine a lot to photograph my daughter. I enjoy the range more than the 18-55 range, and the constant f2.8 is useful. However, it is not a macro lens; you can sort of do close-ups with it, but IMHO it's no better than the kit lens for that kind of use. And in terms of IQ, you might not notice much difference from your 18-55 IS.

The 60 macro is a terrific lens in every respect: sharp, fast-focusing, great colour and contrast, very useful focal range on a crop camera. For close-ups, it's "the business". For true macro, it's also "the business", but you have to get in very close to your subject. No problem for flowers and inanimate objects, but a little more difficult for insects. As a general lens, I love the ability to get close to my subject, and I prefer this lens to my 85 f1.8 for portraits. Downside for you: primes are less flexible for fast-moving children. Also, the focal length is quite close to your 85 f1.8 (although they are two completely different lenses).

In your shoes, of the two, I'd get the macro; buy it used, then if you don't like it, you can sell it without losing much.

i'd go with the macro. it could open up a whole new field of photography and subjects for you.
also do note that you dont need to cover every millimeter.
honestly, you could probably do just fine without the 18-55 or a replacement for it.
personally, i dont like having lenses that are too close in focal lengths.
I think the 11-16 and the 30 1.4 complement each other nicely. and the jump to 85 is pretty useful since you could always just use your feet.
alot of people may disagree with "foot zooming" but for me, it makes me work more the shot

Thanks for your input everyone. I'm a big fan of primes and find I get much more creative with them.

Do those that have the 60 find it too sharp in some cases for portraits?