Hi, I have a Flobeds E. King latex bed that I'd like to use more flexibly.  It is in my guest bedroom, and since the foundations AND cores are actually TwinXL pieces, kept together by an E.King mattress cover/encasement, I'd really like the option to split them into two TwinXL beds when the room is being used by kids.  I found this cover/encasement and it seems like JUST what I need, but it is a bit pricey: http://www.sleeplikeabear.com/product/COV-WOL-018 Can anyone recommend a cheaper option for this purpose?  I've found the very cheap allergy covers, and a few thin cotton (or, ugh, polyester) encasements that don't offer any real "topper" effect, and that's not what I'm looking for.  I do want the topper layer built-in, and for the beds to look like "real" mattresses when they're zipped up.  I hope I'm being clear, if not please let me know! :)  The cores are two layers of 3" latex and one 2" layer of latex convolute.  Thanks so much!