Tough question to answer. The budget can diminish quickly when trying to stock up on things.
I would look at a couple of spinners (Panther Martins, Rooster Tails, etc.) as well as some Kastmasters to start. you can use these for just about anything in Colorado. These will be the least expensive. (50 cents to $3.00/piece)
The next thing I would look at is some crank baits that look like shad - maybe one that runs shallow (floating) and a deep diver (floating or sinking). Count on anything from the dollar bin to $10 each. I like rattle traps and I've had a Rapala "teeny we R" and a "deep we R" for many years and have caught a ton of fish on both.
Then I would look at some tube jigs - white or pumpkin in color. (3 or 4 dollars for some tube jigs and some jig heads).
That will get you started and keep your attention for a while
An alternative would be to look on craigslist.org or ebay.com for people selling whole lots of tackle (or their tackle box) as well as garage sales - it's a quick and easy way to get an assortment at a small price.