Hi gatpapa,
Although it’s not a great lifespan … you were fortunate to get 6 “reasonable” years out of a hotel mattress which is more than many others have experienced. You can read a little more about hotel mattresses in post #3 here.
The best suggestion I would have is to make sure you’ve read the tutorial post here which has all the basic information, steps, and guidelines that can help you choose the perfect mattress for you … and know how and why to avoid the worst ones.
Your budget is certainly enough to find a very good quality/value mattress. I’m not sure where you are in MA but some of the better options or possibilities I’m aware of in the Boston area and south are listed in post #2 here and in the Springfield area in post #4 here. You have some very good options available to you.
I’m looking forward to finding out what you end up choosing and of course any comments or questions you may have along the way.
Phoenix