I would recommend for $200-$300 Fisher F22 $229 new & can be used while raining; Teknetics Minuteman $199 with coupon code from authorized dealer. If it detects iron, iron flashes on screen so you don't get fooled. Both have big numerical ID.
Teknetics Digitek $129 but sale may end 11/30 and you may need to get a 26" lower rod if you are over 5' 6". Marketed as a kids detector, but detects coins to 9" with volume control, sensitivity control, discrimination control, and notches. Has a big numerical ID.
Many say the Bounty Hinter Land Ranger PRO is the best under $300. Multiple search modes, like high trash rejection is turn on and go; lower discrimination programs have ability to ground balance. It's also marketed as a Teknetics for $299 with coupon code.
Teknetics Gamma 6000 & Bounty Hunter Platinum would be great buys for under $200 used. Perhaps you could get a Garrett AT Pro used for $300-$350.
The Ace 250s I had could not ID a dime beyond 4". But almost right away with the AT Pro I got a beep that read dime on every pass. It was a dime at 7" in a park that gets detected maybe 100 days a year and that dime may have sat there for 30 years. Soil was dry, very hard, and moderately mineralized. Get the best you can afford.
Some user satisfaction ratings & what different detectors cost new can be found at the website
http://metaldetectorreviews.net/ Hope this helps. Best wishes, George