Good post! I'm glad that you were able to test fire several firearms before coming up with your "short list" to choose from. All too often, a new shooter merely chooses a firearm because it LOOKS "cool", or because of the caliber. At least you KNOW how those test-fired firearms feel in your hand and how they shoot.
Shop around! Compare the prices at as many gun stores and gun shows as possible. Keep your eyes open for any advertised special prices. If you find what you want at a gun show, "haggle" with the dealer (they expect that). If the gun show dealer comes up with a reasonable price, don't mind "haggling" with him some more! Maybe politely ask if he'll "sweeten the deal" a bit, by throwing in some accessories and/or ammo.
Yes, a cash sale will often give you a bit of a discount, but not always. Just don't mind asking if they'll come down in the price for a cash transaction.
Used? New? That's going to be entirely up to you, but for your FIRST-ever firearm, I'd suggest that you get something NEW. That first firearm will be all YOURS, without a previous owner. Besides, it will come with some sort of warranty that you can be sure of, instead of a used firearm that is no longer under any sort of warranty.
If your choice is based solely upon the cost, and if you were "rich", you would have bought a better brand or model, here are a few suggestions:
Don't compromise your WANT! If you're short on cash, don't get something that is "second best". Save up for the BEST! Maybe tell your relatives and friends that you'd rather have CASH for Christmas, your upcoming birthday, etc. Work a few hours of over-time on your job, if possible, until you have enough. Re-cycle aluminum cans! Sell something that you no longer use on E-Bay, or in your local newspaper. Ask your relatives if they'll give you a short-term loan. Hold a "garage sale". Do without a few "luxuries" for awhile.
Several years back, I wanted a rifle that was going to set me back quite a bit, but I didn't want to dip into the savings account. I needed to come up with $1,200. At one point, I thought that I might take me 6 months to come up with that amount, so you can understand how I surprised myself by being able to come up with over $2,000 in just ONE month by using several of the above-mentioned "money makers"!