I don't think you can find a detector that will give you a 100% accurate idea every time. The ID machines, like the MXT, DFX, and XLT are good machines--but they aren't accurate always either. And they are heavier than the Ace 250. A used XLT might be in your price range, though. In order to find a gold ring, you'll have to dig foil and aluminum. No way around it. But being a "selective" digger will greatly reduce the numbers of other great (and VALUABLE) finds you'll make. High grade deep silver coins, old coppers, and valuable relics could pass by unnoticed. If you're only wanting silver (and willing to sacrifice all relics, gold, and platinum), you could probably dig only targets that peg in the 80's on an ID machine like those mentioned above--but keep in mind that a deep silver coin may sound like a penny depending on how it is situated in the soil, etc. So you'd be missing those too.
So basically your decision seems to be this: To metal detect or not to metal detect! They don't make machines that are 100% accurate currently. So you should perhaps either resolve to get yourself in shape for the task ahead (digging LOTS of holes in the ground), or give up the idea entirely. When I started, I had to pay close attention to my posture for swinging a detector. I also had to gradually increase my hunting time over several months so that I could be out for several 8-hour days back to back without pain in my arms, legs, back, or elbows. No one has said much about good posture on this website so far, but it is VERY important. And we always have to monitor it so that we have as little wear and tear on our bodies as possible. Knee pads or back braces seem to help some people. Metal detecting ain't easy! And it's especially not easy to do the type of detecting that it takes to make the good finds! Some things to consider:
1. Research is key! If you have an aversion to hitting the books, looking for old maps, driving around with a GPS system to pinpoint sites, spending hours in libraries, or the like...your finds will not be as good. Unless you get lucky.
2. Time spent out in the field to find old homesites, Civil War campsites, old picnic groves, ferry sites, long-abandoned parks, etc., is rigorous. I have spent countless hours tearing through the brush and woods to find the location of sites. This type of pinpointing--after you have seen all the information that you could find about the site's location--is still considered research (I call it "field research"). All this work is, in fact, still just a prelude to a successful hunt.
3. The actual hunt: Only taking the time to exhaust ALL the good targets will net you the most valuable finds, be they silver, gold, platinum, lead, brass, or copper. And there are extremely valuable items made of each of these metals.
These things in mind, you should consider your decision carefully. Another option I can thin, of for you is one that would net you some nice gold, silver, and platinum items over time, and that is beach hunting. You could use a long-handled sand scoop to get your targets without bending over to recover them. You'd still have to scoop up a lot of foil and pulltabs to get those gold rings, but it would be much easier. So if you live close to the coast, that seems like a more viable venue for you.
Regards,
Buckleboy
I'm exhausted every time I get back from a long day out! But the key is to make sure that I'm good to go and pain-free the next morning.