Hey there bvdk.
Welcome to the Mattress UnderGround.
Regardless of your price range and budget, you want a mattress that will address your PPP’s (Posture and Alignment, Personal Preferences, and Pressure Relief issues).
Choosing a mattress based solely on price isn’t the best approach. First, focus on finding a mattress that is comfortable, regardless of cost. Once you have identified what feels right, then search for options that offer the same comfort and features within your budget. It’s important to keep price secondary at first, so you can make a decision based on true comfort, without being influenced by cost. This ensures your selection genuinely reflects what will make you feel comfortable.
The other factors that need to be considered before someone can offer personalized advice is to understand what your age, height, weight, sleep position and if known, what you actually have been comfortable on in the past. Additionally, always offer the size mattress you are looking for.
Taking a peek at our tutorials will also provide a bit more understanding how materials, foams, springs and other component parts of the mattress work, and work together.
A thick topper may be made to an ILD of 44 or 14, and will have very different feels. As a general rule a 3" topper of a certain composition will change the way the mattress feels entirely, 1 or 2" will generally add a touch of reduced firmness, contouring and pressure relief necessary to make a slightly firm mattress just right.
It is not actually clear that you need a softer more cradling mattress. It may be what ultimately works, but much is dependent upon the material components used in the mattress. For example, the newer Brooklyn Bedding Titan Plus Elite, is a mattress designated in the plus sized category. Mainly because it offers a very supportive 13.5 gauge firm spring support, but it also has a very cushy luxury, slightly cuddling feeling comfort layer that incorporates a layer of microcoils in place of memory foam. Here you get better air flow for cooling, contouring and cuddling between the microcoils and the comfort layer, and a ton of support with 6" of comfort above that support layer, that is right at the cusp of balancing firmer support with slight cuddling comfort.
A mattress does not need to be all foam to accomplish that.
I am quite certain if you collaborated with on of TMU’s latex specialists, like @DIYMattress, @Sleep_EZ, @Arizona_Premium and @Latex_Mattress_Fact1 could work withing that budget to find you something that hits all the checkboxes.
The original Leesa and Nolah all foam versions might check your preferences right out of the box, as might the Helix Core line, it is just a matter of what you are used to sleeping on and your preferences and expectations based on body profile criteria.
Once we can gather a bit more information, perhaps it will offer enough information to help you narrow down some options.
Hope this helps get you started in the right direction.
Maverick