Hi transcendlimits,
While any mattress may be a suitable choice for some people … you can read my thoughts about the pros and cons of airbeds in this article and I would tend to avoid them unless you have a particularly compelling reason not to.
I would make sure at the very least that you know the type and quality of all the comfort layers in any mattress you consider so that your mattress doesn’t have any lower quality materials or obvious weak links (see this article) and if you aren’t able to find out the quality of the layers in any mattress you purchase then I would pass the mattress by and I would tend to avoid the major brands anyway (see the guidelines here).
I also wouldn’t buy a mattress with any sense of urgency that comes from so called “sale” prices because good quality/value mattresses are available every day of the year (see post #5 here).
If for some reason you are committed to an airbed and there are no other types of mattresses that will do then there are some other options available to you that are listed in post #3 here that may be in a much better quality/value range than the Sleep Number you are considering.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more the most suitable choices and more meaningful comparisons between mattresses.
Phoenix