Free: Contests & Raffles.
First I would still shop for a new scope. Plenty of options out there just got to find the right one for you. I would look into a low powered leupold MK ar or VX hog. 22LR will not drop most coyotes unless you hit the nervous system. Get a 22 magnum and you will drop a lot more coyotes. We have shot a ton of coyotes and it always surprises me with a 40g hollow point how many drop with a 22 mag.
This is a very nice little red-dot for under $70 bucks (Bushnell Trophy TRS) I'd put this on your 223. Carry a spare battery as it is only battery powered (only down side).I have a few of these and they are a great value for the money.https://www.amazon.com/Bushnell-Trophy-TRS-25-Sight-Riflescope/dp/B00200E0HM/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1502141897&sr=1-1&keywords=bushnell+red+dot