I missing the bottom board at the end of my malm bed...I lost it in the way of moving to a different apartment...does ikea sell some stuff separate for instance this board I need or would I have to buy the whole bed parts again all together

There's a phone number on your instructions for calling if you are missing parts.

I think that would be best answered by IKEA!

I saw separated part for bed frame on a display pallet on the sale floor but I didn't see any sale price

I dont think they sell separately but they might have boards that you can fit. I would call before going back

They also sell spare parts in their clearance section.

Ikea does sell spare parts like additional screws, nuts, bolts but I can't confirm if they would have what you need. The best thing is to call or visit the store directly with the make and model # and I am sure they can help you out. Also take pics of the bed and of the area with the missing piece to show the staff if you chose to visit the store.