For your conditions you have lots of cheap choices, as previously pointed out. I have a whole bunch of jackets, cheap to dear. On the former end, see what Nashbar has. I got a nice GBW Function II Winstopper for $110 this fall (2007-08 model) with zip off sleeves, which is to say you can get a bit of pit-opening without removing the sleeves. I love it. They subsequently dropped the price to $84. Super bang for buck shell.

I also got a Bellwether putatively waterproof shell. I paid $90ish. Pitzips (conventional opening from mid-upper arm to lower chest) and back vent. Excellent bang for buck.

Old PI Zepphr windproof and water resistant with removable sleeves (again giving you some pit-zipping venting) and back vent. Somebody got it on sale for me, 80ish. Very good.

All of these are packable in a jersey pocket. I'm not pimping any specific brands. I would say look for pitzips, and back vent. A double-action zipper, opening from the bottom, if you can find it, is a venting-adjustability plus. You can always hire a seamstress to put one in on a regular-zip jacket.

Check out Showers Pass. $230 for Elite II gives you full venting capability, plus waterproof eVent. Very, very popular in the NW. Some quality control and unresponsiveness to customer's asking for repair/replacement reported, but most users seem to be very happy. They also make some less-expensive non-eVent Century and other models that get some very good reviews.

You might also consider alpine-sports shells. They often go on sale for overstocks and closeouts.

I've got softshells and rainshells from Arc Teryx, Mountain Hardwear, Marmot and REI that all work well. I lost a lot of weight, so some jackets became too big, and I looked for great deals when I downsized. I also have two sons who like to ride when they visit mom and dad, so they can use my stuff.

You can't beat Windstopper for stopping windchill dead in its tracks. It's the gold standard. Lots of respected bikewear companies use it. Most shells and fleece-line softshells with it are water resistant. We're seeing stretchy Windstopper ("X-lite" and "X-Fast"), and it really "hugs" you. This isn't a great time to find it on discount. You'd have to wait for warmer weather.