If you are talking about values of actual household items like furniture, art works, etc then you can find values on line or at second hand stores (assuming it's not brand new furniture). One thing my STBX wife did was look on Ebay for similar items, and that can give you an idea of real value.

Another thought is that when he values them really high, you can value them really low and then you both average them out and it should bring them to their normal value. I'M JOKING ON THIS.

You can research "how to value used items" and get several search engines that might help you value some items.

Keep in mind that with furniture, you may have bought it new, but it is used now and doesn't have the value it used to have. Appraised value on jewelry is for insurance purposes, but is NOT the value that it will be sold for to others, a jeweler or a pawn shop. Jewelry just doesn't get sold for the appraised value.

Some things have no value, except sentimental value and you can't put a dollar value on them.

I don't know how amicable your situation is between the both of you, but if its not a nasty one, possibly get some sticker dots or whatnot and put them on the things you each want. Anything that has stickers from both, have a discussion about and compromise. One person gets this, while the other gets that. use whatever reasons you have as to why you want the item.

Otherwise, you can decide who wants to keep the item and who wants the money for it.