Let's start from the bottom up.
To support a large man, you will need quality products...most important is the quality of the mattress.
The products that support the mattress, you can buy cheaply enough...so lets start with the foundation.
A steel bed frame is optional and not a necessary item.
A good foundation, (boxspring), you can get at Sam's Club or Costco at the lowest price I've seen anywhere...about $100 in queen.
They are simply made, but very strong.
You will need a foundation so that his sleep apnea can be addressed....which we will do first.
At the head of the foundation, (or under the back legs of the frame, if you opt to buy one), you'll add bed risers...like the ones shown in this link.
Adding these to the head of the bed will give the mattress a tilt. You won't even notice to lay on, but he will breathe easier with them.
These are available on-line and at stores like Big Lots, Target and Walmart.
When it comes to the mattress, an individually pocketed coil unit will contour to the body and maintain the spine's natural alignment.
You'd be amazed at how well this relieves back pain.
There are many brands that off this type of coil unit, but it's also important to buy a mattress with NO Memory Foam in it.
Memory foam is the worst upholstery material available...specifically designed to require frequent replacing.
When you're on a tight budget, it's important that you don't waste the money you have. Memory foam is just that...a complete waste of money.
Unfortunately, most mattresses have memory foam in them...especially the name brands. So, you will need to avoid those.
My best mattress may not be in your budget, but will last a very long time...making it the least expensive when averaged over the many years you will have it.
That will be the Natura of Canada Greenspring Plush Eurotop mattress...shown here, at the top of the page:
Latex is extremely comfortable, sleeps cool, and lasts for decades.
Both mattresses are very comfortable and provide excellent support.
And, there's no memory foam in either of them.
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