Hi Yenal,
Post #2 here includes some of the better calue choices in your area (including Foam Sweet Foam which I also believe is one of your better options).
As far as the choices between memory foam and other materials, this is strictly a matter of personal preference and whether you prefer slow or fast response materials. Regardless of which you prefer though … every type of material has lower and higher quality choices and knowing the quality of the material (the density of any memory foam or polyfoam in your mattress is the most important way to know the quality and durability of these types of foam) is important.
Budget is also a matter of personal preference. There is good and poor “value” in every budget range and connecting with manufacturers and retail outlets that are able and willing to tell you the difference is just as important as choosing a mattress that is “comfortable” in a showroom but may not be as comfortable when you sleep on it or a year down the road if it contains lower quality materials that will lose their comfort and support much more quickly (and loss of comfort and support is not covered by warranty).
As TexMac also mentioned … nothing is “free” when you buy a mattress whether this is a foundation, delivery, exchange policies, or any other “benefit” that comes with a mattress purchase. It is simply added to (or included in) the cost of the mattress and/or whatever else you are buying. The only thing that is really “free” is the knowledge and experience of the people you are working with and their ability to help you make your best choices … and this is much more valuable than a “free foundation” which really isn’t free at all.
There is more information here about the pros and cons of memory foam but keep in mind that there are hundreds of different types of memory foam which will perform and feel differently. Some of these are much “hotter” than others although it is true that memory foam in general tends to sleep hotter than other materials such as latex, polyfoam, or some of the other materials that are used in the comfort layers of a mattress. Scanning the overviews in the mattresses section of the site can help give you enough basic information to ask better questions when you are mattress shopping. Post #9 here has more information about the many different qualities of different types of memory foam.
Don’t forget too that the better manufacturers and retailers in your area will already know this and will help you know and test the differences for yourself. While some basic information is always a good idea to help you know when you are dealing with “mattress people” instead of more typical “salespeople” … I would avoid the tendency to “become” an expert and focus more on connecting with the experts who already know (and are willing to share) what you would otherwise need to learn.
Phoenix