Hi Mjr3126,
There are some suggestions for purchasing a mattress for a guest bedroom in post #2 here that should be helpful.
Subject to confirming that any retailer or manufacturer on the list you wish to deal with is completely transparent about the materials and components in their mattresses (see this article) and to making sure that any mattress you are considering meets the quality/value guidelines here … the better options or possibilities I’m aware of in and around the Indianapolis area are listed in post #2 here.
Outside of any local options that may be available to you … if you are also considering online choices then some of the better lower budget online options I’m aware of are listed at the end of post #4 here and the other online lists it links to.
Phoenix