If it were me, I’d opt for the older boat and get something bigger and with more power. I think this is far superior in many ways to buying a newer smaller rig. As far as reliability goes, I see just as many newer motors have problems as the older ones.
Outboard engines can last a LONG time and be quite bullet proof, if properly cared for. The 30 year old 65 hp Merc I had on a 1968 Starcraft Super-Sport 16’ started easily, ran like a top, and never gave me one minute of trouble. I’m sure it had many hundreds of hours on it. I wouldn’t worry about the age if it has been well kept. Ask if it has been winterized every fall, given fresh lower unit oil every spring, not run in salt water, has good lower unit seals, and hasn’t sat unused. Motors that sit unused for long periods of time are prone to internal corrosion, cracking seals, gummed up carbs, etc. Ask to take it out for a test run on the nearest lake. Observe how it starts, idles, accelerates, and runs flat out. Make sure the cooling impeller is good and squirting a solid stream of water out the back. Shut the motor off and look carefully for any signs of oil floating on the surface of the water that might indicate bad seals. After taking the boat back out of the water, drain a little of the lower unit gear oil and see if it looks normal. A light brown milky color indicates water is getting in there, and the seals on the prop shaft are probably bad.
Don’t let me scare you. It isn’t all that hard to find a well kept used boat for a very reasonable price. Then you can use and enjoy it, then get all or more of your money back when it comes time to sell.
Again, my recommendation on your budget is an older 16’ OR BIGGER deep-v with console/windshield (brands: Crestliner, Starcraft, Smokercraft, Lund, Tracker, Sylvan, Fisher, etc.), with at least a 40 HP OR BIGGER 2-stroke outboard (brands: Mercury, Mariner, Johnson, Evinrude, Suzuki, or Yamaha. Stay away from “Force”). Chances are, if you settle for less of a rig than this then you will be back in the market again for a better rig next year.
Check out http://www.boattraderonline.com. They have 116,000 used boats listed, and tons of criteria for searching. You might have to drive a few miles to pick one up, but it can be well worth it. Some sellers will meet you half way.
Here are a few for you to look at. Remember you can negotiate on the price:
http://adcache.boattraderonline.com/6/0/2/78306102.htm
http://adcache.boattraderonline.com/6/3/2/78224232.htm
http://adcache.boattraderonline.com/6/3/5/76173235.htm
http://www.boattraderonline.com/caddetail.html?/ad-cache/6/8/5/74928085.htm
http://adcache.boattraderonline.com/6/4/5/74885745.htm
http://adcache.boattraderonline.com/6/2/3/75200423.htm
http://adcache.boattraderonline.com/6/3/3/78343133.htm
http://adcache.boattraderonline.com/6/0/8/76739508.htm
http://adcache.boattraderonline.com/6/3/3/78224233.htm
http://adcache.boattraderonline.com/6/7/8/78378778.htm
Have fun!